liblpfk: src/liblpfk.c@071056e12321 (annotated)

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src/liblpfk.c@071056e12321 (annotated)

src/liblpfk.c

Tue, 26 Aug 2008 18:45:10 +0100

author: Philip Pemberton <philpem@philpem.me.uk>
date: Tue, 26 Aug 2008 18:45:10 +0100
changeset 2: 071056e12321
parent 1: 3e775df109e6
child 3: 93f5d26366ad
permissions: -rw-r--r--

lpfk_open now calls lpfk_enable.
also made LPFK_CTX the first parameter in all functions (for consistency)

 /****************************************************************************
  * Project:		liblpfk
  * Purpose:		Driver library for the IBM 6094-020 Lighted Program Function
  * 				Keyboard.
  * Version:		1.0
  * Author:		Philip Pemberton <philpem@philpem.me.uk>
  *
  * The latest version of this library is available from
  * <http://www.philpem.me.uk/code/liblpfk/>.
  *
  * Copyright (c) 2008, Philip Pemberton
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * 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.
  *  * Neither the name of the project 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.
  ****************************************************************************/
 /**
  * @file	liblpfk.c
  * @brief	liblpfk library, main source
  */
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <termios.h>
 #include <sys/ioctl.h>
 #include <time.h>
 #include <string.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include "liblpfk.h"
 /* lpfk_open {{{ */
 int lpfk_open(LPFK_CTX *ctx, const char *port)
 {
 	struct termios newtio;
 	int status;
 	int fd;
 	int i;
 	// open the serial port
 	fd = open(port, O_RDWR | O_NOCTTY | O_NDELAY);
 	if (fd < 0) return LPFK_E_PORT_OPEN;
 	// save current port settings
 	tcgetattr(fd, &ctx->oldtio);
 	// set up new parameters
 	memset(&newtio, 0, sizeof(newtio));
 	// 9600 baud, 8 bits, parity enabled, odd parity
 	newtio.c_cflag = B9600 | CS8 | PARENB | PARODD | CLOCAL | CREAD;
 	newtio.c_iflag = 0;
 	newtio.c_oflag = 0;
 	// set input mode -- non canonical, no echo
 	newtio.c_lflag = 0;
 	// inter-character timer unused
 	newtio.c_cc[VTIME] = 0;
 	// read does not block waiting for characters if there are none in the buffer
 	newtio.c_cc[VMIN]  = 0;
 	// flush input buffer
 	tcflush(fd, TCIFLUSH);
 	// set new port config
 	tcsetattr(fd, TCSANOW, &newtio);
 	// set RTS true to pull the LPFK out of reset
 	ioctl(fd, TIOCMGET, &status);
 	status |= TIOCM_RTS;
 	ioctl(fd, TIOCMSET, &status);
 	// wait a few seconds for the LPFK to become ready
 	sleep(2);
 	// 0x06: READ CONFIGURATION. LPFK sends 0x03 in response.
 	// Try five times to wake it up.
 	status = false;
 	for (i=0; i<5; i++) {
 		unsigned char buf;
 		time_t tm;
 		// Send 0x06: READ CONFIGURATION, loop on failure
 		if (write(fd, "\x06", 1) < 1) {
 			continue;
 		}
 		// save current time (in seconds)
 		tm = time(NULL);
 		// loop until 2 seconds have passed, or LPFK responds
 		status = false;
 		do {
 			// read data, loop if not successful
 			if (read(fd, &buf, 1) < 1) {
 				continue;
 			}
 			// we got some data, what is it?
 			if (buf == 0x03) {
 				// 0x03 -- correct response. we're done.
 				status = true;
 			}
 		} while (((time(NULL) - tm) < 2) && (!status));
 		// exit loop if we got the LPFK to talk
 		if (status) {
 			break;
 		}
 	}
 	// Did the LPFK respond?
 	if (!status) {
 		// LPFK isn't talking. Restore serial port state and exit.
 		tcsetattr(fd, TCSANOW, &ctx->oldtio);
 		close(fd);
 		return LPFK_E_NOT_PRESENT;
 	} else {
 		// Initialise LPFK context
 		ctx->led_mask = 0;
 		ctx->fd = fd;
 		// Disable LPFK keyboard scanning
 		lpfk_enable(ctx, false);
 		// Return OK status
 		return LPFK_E_OK;
 	}
 }
 /* }}} */
 /* lpfk_close {{{ */
 int lpfk_close(LPFK_CTX *ctx)
 {
 	int status;
 	// 0x09: DISABLE. Stop the LPFK responding to keystrokes.
 	write(ctx->fd, "\x09", 1);
 	// turn all the LEDs off
 	lpfk_set_leds(ctx, false);
 	// set RTS false to put the LPFK into reset
 	ioctl(ctx->fd, TIOCMGET, &status);
 	status &= ~TIOCM_RTS;
 	ioctl(ctx->fd, TIOCMSET, &status);
 	// Restore the port state and close the serial port.
 	tcsetattr(ctx->fd, TCSANOW, &ctx->oldtio);
 	close(ctx->fd);
 	// Done!
 	return LPFK_E_OK;
 }
 /* }}} */
 /* lpfk_enable {{{ */
 int lpfk_enable(LPFK_CTX *ctx, int val)
 {
 	if (val) {
 		// val == true, enable the LPFK
 		if (write(ctx->fd, "\x08", 1) != 1) {
 			ctx->enabled = true;
 			return LPFK_E_COMMS;
 		}
 	} else {
 		// val == false, disable the LPFK
 		if (write(ctx->fd, "\x09", 1) != 1) {
 			return LPFK_E_COMMS;
 		}
 	}
 	// update the context, return success
 	ctx->enabled = val;
 	return LPFK_E_OK;
 }
 /* }}} */
 /* lpfk_set_led_cached {{{ */
 int lpfk_set_led_cached(LPFK_CTX *ctx, const int num, const int state)
 {
 	int i;
 	time_t tm;
 	unsigned long mask, leds;
 	unsigned char buf[5];
 	unsigned char status;
 	// check parameters
 	if ((num < 0) || (num > 31)) {
 		return LPFK_E_PARAM;
 	}
 	// parameters OK, now build the LED mask
 	mask = (0x80 >> (num % 8)) << ((3 - (num / 8)) * 8);
 	// mask the specified bit
 	if (state) {
 		ctx->led_mask |= mask;
 	} else {
 		ctx->led_mask &= ~mask;
 	}
 	return LPFK_E_OK;
 }
 /* }}} */
 /* lpfk_set_leds_cached {{{ */
 int lpfk_set_leds_cached(LPFK_CTX *ctx, const int state)
 {
 	int i;
 	time_t tm;
 	unsigned long leds;
 	unsigned char buf[5];
 	unsigned char status;
 	if (state) {
 		// all LEDs on
 		ctx->led_mask = 0xFFFFFFFF;
 	} else {
 		// all LEDs off
 		ctx->led_mask = 0x00000000;
 	}
 	return LPFK_E_OK;
 }
 /* }}} */
 /* lpfk_update_leds {{{ */
 int lpfk_update_leds(LPFK_CTX *ctx)
 {
 	int i;
 	time_t tm;
 	unsigned char buf[5];
 	unsigned char status;
 	// send new LED mask to the LPFK
 	buf[0] = 0x94;
 	buf[1] = ctx->led_mask >> 24;
 	buf[2] = ctx->led_mask >> 16;
 	buf[3] = ctx->led_mask >> 8;
 	buf[4] = ctx->led_mask & 0xff;
 	// make 5 attempts to set the LEDs
 	for (i=0; i<5; i++) {
 		if (write(ctx->fd, &buf, 5) < 5) {
 			continue;
 		}
 		// check for response -- 0x81 = OK, 0x80 = retransmit
 		// save current time (in seconds)
 		tm = time(NULL);
 		// loop until 2 seconds have passed, or LPFK responds
 		status = 0x00;
 		do {
 			// read data, loop if not successful
 			if (read(ctx->fd, &status, 1) < 1) {
 				continue;
 			}
 			// we got some data, what is it?
 			if (status == 0x81) {
 				// 0x81 -- received successfully
 				break;
 			}
 		} while ((time(NULL) - tm) < 2);
 		// status OK?
 		if (status == 0x81) {
 			// 0x81: OK
 			break;
 		} else if (status == 0x80) {
 			// 0x80: Retransmit request
 			continue;
 		}
 	}
 	return LPFK_E_OK;
 }
 /* }}} */
 /* lpfk_set_led {{{ */
 int lpfk_set_led(LPFK_CTX *ctx, const int num, const int state)
 {
 	lpfk_set_led_cached(ctx, num, state);
 	return lpfk_update_leds(ctx);
 }
 /* }}} */
 /* lpfk_set_leds {{{ */
 int lpfk_set_leds(LPFK_CTX *ctx, const int state)
 {
 	lpfk_set_leds_cached(ctx, state);
 	return lpfk_update_leds(ctx);
 }
 /* }}} */
 /* lpfk_get_led {{{ */
 int lpfk_get_led(LPFK_CTX *ctx, const int num)
 {
 	unsigned long mask;
 	// check parameters
 	if ((num < 0) || (num > 31)) {
 		return false;
 	}
 	// parameters OK, now build the LED mask
 	mask = (0x80 >> (num % 8)) << ((3 - (num / 8)) * 8);
 	if (ctx->led_mask & mask) {
 		return true;
 	} else {
 		return false;
 	}
 }
 /* }}} */
 /* lpfk_read {{{ */
 int lpfk_read(LPFK_CTX *ctx)
 {
 	int nbytes;
 	unsigned char key;
 	// make sure the LPFK is enabled before trying to read a scancode
 	if (!ctx->enabled) {
 		return LPFK_E_NOT_ENABLED;
 	}
 	// try and read a byte (keycode) from the LPFK
 	nbytes = read(ctx->fd, &key, 1);
 	if ((nbytes < 1) || (key > 31)) {
 		// no keys buffered, or keycode invalid.
 		return -1;
 	} else {
 		// key buffered, pass it along.
 		return key;
 	}
 }
 /* }}} */

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src/liblpfk.c@071056e12321 (annotated)

src/liblpfk.c