pgm.c

这是一个非常有价值的参考代码

/*
 * avrdude - A Downloader/Uploader for AVR device programmers
 * Copyright (C) 2002-2004  Brian S. Dean <[e-mail]>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* $Id: pgm.c,v 1.18 2004/12/22 01:52:45 bdean Exp $ */

#include "ac_cfg.h"

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

#include "pgm.h"

extern char * progname;

static int  pgm_default_2 (struct programmer_t *, AVRPART *);
static void pgm_default_4 (struct programmer_t *);
static int  pgm_default_5 (struct programmer_t *, unsigned char cmd[4],
                    unsigned char res[4]);
static void pgm_default_6 (struct programmer_t *, char *);


static int pgm_default_open (struct programmer_t *pgm, char * name)
{
  fprintf (stderr, "\n%s: Fatal error: Programmer does not support open()",
               progname);
  exit(1);
}

static int  pgm_default_led (struct programmer_t * pgm, int value)
{
  /*
   * If programmer has no LEDs, just do nothing.
   */
  return 0;
}


static void pgm_default_powerup_powerdown (struct programmer_t * pgm)
{
  /*
   * If programmer does not support powerup/down, just do nothing.
   */
}


PROGRAMMER * pgm_new(void)
{
  int i;
  PROGRAMMER * pgm;

  pgm = (PROGRAMMER *)malloc(sizeof(*pgm));
  if (pgm == NULL) {
    fprintf(stderr, "%s: out of memory allocating programmer structure\n",
            progname);
    exit(1);
  }

  memset(pgm, 0, sizeof(*pgm));

  pgm->id = lcreat(NULL, 0);
  pgm->desc[0] = 0;
  pgm->type[0] = 0;
  pgm->config_file[0] = 0;
  pgm->lineno = 0;
  pgm->baudrate = 0;

  for (i=0; i<N_PINS; i++)
    pgm->pinno[i] = 0;

  /*
   * mandatory functions - these are called without checking to see
   * whether they are assigned or not
   */
  pgm->initialize     = pgm_default_2;
  pgm->display        = pgm_default_6;
  pgm->enable         = pgm_default_4;
  pgm->disable        = pgm_default_4;
  pgm->powerup        = pgm_default_powerup_powerdown;
  pgm->powerdown      = pgm_default_powerup_powerdown;
  pgm->program_enable = pgm_default_2;
  pgm->chip_erase     = pgm_default_2;
  pgm->cmd            = pgm_default_5;
  pgm->open           = pgm_default_open;
  pgm->close          = pgm_default_4;

  /*
   * predefined functions - these functions have a valid default
   * implementation. Hence, they don't need to be defined in
   * the programmer.
   */
  pgm->rdy_led        = pgm_default_led;
  pgm->err_led        = pgm_default_led;
  pgm->pgm_led        = pgm_default_led;
  pgm->vfy_led        = pgm_default_led;

  /*
   * optional functions - these are checked to make sure they are
   * assigned before they are called
   */
  pgm->paged_write    = NULL;
  pgm->paged_load     = NULL;
  pgm->write_setup    = NULL;
  pgm->write_byte     = NULL;
  pgm->read_byte      = NULL;
  pgm->read_sig_bytes = NULL;
  pgm->set_vtarget    = NULL;
  pgm->set_varef      = NULL;
  pgm->set_fosc       = NULL;

  return pgm;
}


static void pgm_default(void)
{
  fprintf(stderr, "%s: programmer operation not supported\n", progname);
}


static int  pgm_default_2 (struct programmer_t * pgm, AVRPART * p)
{
  pgm_default();
  return -1;
}

static void pgm_default_4 (struct programmer_t * pgm)
{
  pgm_default();
}

static int  pgm_default_5 (struct programmer_t * pgm, unsigned char cmd[4],
                    unsigned char res[4])
{
  pgm_default();
  return -1;
}

static void pgm_default_6 (struct programmer_t * pgm, char * p)
{
  pgm_default();
}