avr.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) 2000-2004  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: avr.c,v 1.65 2005/09/21 01:26:54 bdean Exp $ */

#include "ac_cfg.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <time.h>


#include "avr.h"
#include "lists.h"
#include "pindefs.h"
#include "ppi.h"
#include "safemode.h"

#define DEBUG 0

extern char       * progname;
extern char         progbuf[];
extern PROGRAMMER * pgm;


extern int do_cycles;


int avr_read_byte_default(PROGRAMMER * pgm, AVRPART * p, AVRMEM * mem, 
                          unsigned long addr, unsigned char * value)
{
  unsigned char cmd[4];
  unsigned char res[4];
  unsigned char data;
  OPCODE * readop;

  pgm->pgm_led(pgm, ON);
  pgm->err_led(pgm, OFF);

  /*
   * figure out what opcode to use
   */
  if (mem->op[AVR_OP_READ_LO]) {
    if (addr & 0x00000001)
      readop = mem->op[AVR_OP_READ_HI];
    else
      readop = mem->op[AVR_OP_READ_LO];
    addr = addr / 2;
  }
  else {
    readop = mem->op[AVR_OP_READ];
  }

  if (readop == NULL) {
#if DEBUG
    fprintf(stderr, 
            "avr_read_byte(): operation not supported on memory type \"%s\"\n",
            p->desc);
#endif
    return -1;
  }

  memset(cmd, 0, sizeof(cmd));

  avr_set_bits(readop, cmd);
  avr_set_addr(readop, cmd, addr);
  pgm->cmd(pgm, cmd, res);
  data = 0;
  avr_get_output(readop, res, &data);

  pgm->pgm_led(pgm, OFF);

  *value = data;

  return 0;
}


/*
 * read a byte of data from the indicated memory region
 */
int avr_read_byte(PROGRAMMER * pgm, AVRPART * p, AVRMEM * mem, 
                  unsigned long addr, unsigned char * value)
{
  int rc;

  if (pgm->read_byte) {
    rc = pgm->read_byte(pgm, p, mem, addr, value);
    if (rc == 0) {
      return rc;
    }
    /* read_byte() method failed, try again with default. */
  }

  return avr_read_byte_default(pgm, p, mem, addr, value);
}


/*
 * Return the number of "interesting" bytes in a memory buffer,
 * "interesting" being defined as up to the last non-0xff data
 * value. This is useful for determining where to stop when dealing
 * with "flash" memory, since writing 0xff to flash is typically a
 * no-op. Always return an even number since flash is word addressed.
 */
int avr_mem_hiaddr(AVRMEM * mem)
{
  int i, n;

  /* return the highest non-0xff address regardless of how much
     memory was read */
  for (i=mem->size-1; i>0; i--) {
    if (mem->buf[i] != 0xff) {
      n = i+1;
      if (n & 0x01)
        return n+1;
      else
        return n;
    }
  }

  return 0;
}


/*
 * Read the entirety of the specified memory type into the
 * corresponding buffer of the avrpart pointed to by 'p'.  If size =
 * 0, read the entire contents, otherwise, read 'size' bytes.
 *
 * Return the number of bytes read, or < 0 if an error occurs.  
 */
int avr_read(PROGRAMMER * pgm, AVRPART * p, char * memtype, int size, 
             int verbose)
{
  unsigned char    rbyte;
  unsigned long    i;
  unsigned char  * buf;
  AVRMEM * mem;
  int rc;

  mem = avr_locate_mem(p, memtype);
  if (mem == NULL) {
    fprintf(stderr, "No \"%s\" memory for part %s\n",
            memtype, p->desc);
    return -1;
  }

  buf  = mem->buf;
  if (size == 0) {
    size = mem->size;
  }

  /*
   * start with all 0xff
   */
  memset(buf, 0xff, size);

  if ((strcmp(mem->desc, "flash")==0) || (strcmp(mem->desc, "eeprom")==0)) {
    if (pgm->paged_load != NULL) {
      /*
       * the programmer supports a paged mode read, perhaps more
       * efficiently than we can read it directly, so use its routine
       * instead
       */
      if (mem->paged) {
        rc = pgm->paged_load(pgm, p, mem, mem->page_size, size);
        if (rc < 0)
          return rc;
      }
      else {
        rc = pgm->paged_load(pgm, p, mem, pgm->page_size, size);
        if (rc < 0)
          return rc;
      }
      if (strcasecmp(mem->desc, "flash") == 0)
        return avr_mem_hiaddr(mem);
      else
        return rc;
    }
  }

  if (strcmp(mem->desc, "signature") == 0) {
    if (pgm->read_sig_bytes) {
      return pgm->read_sig_bytes(pgm, p, mem);
    }
  }

  for (i=0; i<size; i++) {
    rc = avr_read_byte(pgm, p, mem, i, &rbyte);
    if (rc != 0) {
      fprintf(stderr, "avr_read(): error reading address 0x%04lx\n", i);
      if (rc == -1) 
        fprintf(stderr, 
                "    read operation not supported for memory \"%s\"\n",
                memtype);
      return -2;
    }
    buf[i] = rbyte;
    report_progress(i, size, NULL);
  }

  if (strcasecmp(mem->desc, "flash") == 0)
    return avr_mem_hiaddr(mem);
  else
    return i;
}


/*
 * write a page data at the specified address
 */
int avr_write_page(PROGRAMMER * pgm, AVRPART * p, AVRMEM * mem, 
                   unsigned long addr)
{
  unsigned char cmd[4];
  unsigned char res[4];
  OPCODE * wp;

  wp = mem->op[AVR_OP_WRITEPAGE];
  if (wp == NULL) {
    fprintf(stderr, 
            "avr_write_page(): memory \"%s\" not configured for page writes\n",
            mem->desc);
    return -1;
  }

  /*
   * if this memory is word-addressable, adjust the address
   * accordingly
   */
  if ((mem->op[AVR_OP_LOADPAGE_LO]) || (mem->op[AVR_OP_READ_LO]))
    addr = addr / 2;

  pgm->pgm_led(pgm, ON);
  pgm->err_led(pgm, OFF);

  memset(cmd, 0, sizeof(cmd));

  avr_set_bits(wp, cmd);
  avr_set_addr(wp, cmd, addr);
  pgm->cmd(pgm, cmd, res);

  /*
   * since we don't know what voltage the target AVR is powered by, be
   * conservative and delay the max amount the spec says to wait
   */
  usleep(mem->max_write_delay);

  pgm->pgm_led(pgm, OFF);
  return 0;
}


int avr_write_byte_default(PROGRAMMER * pgm, AVRPART * p, AVRMEM * mem,
                   unsigned long addr, unsigned char data)
{
  unsigned char cmd[4];
  unsigned char res[4];
  unsigned char r;
  int ready;
  int tries;
  unsigned long start_time;
  unsigned long prog_time;
  unsigned char b;
  unsigned short caddr;
  OPCODE * writeop;
  int rc;
  int readok=0;
  struct timeval tv;

  if (!mem->paged) {
    /* 
     * check to see if the write is necessary by reading the existing
     * value and only write if we are changing the value; we can't
     * use this optimization for paged addressing.
     */
    rc = avr_read_byte(pgm, p, mem, addr, &b);
    if (rc != 0) {
      if (rc != -1) {
        return -2;
      }
      /*
       * the read operation is not support on this memory type
       */
    }
    else {
      readok = 1;
      if (b == data) {
        return 0;
      }
    }
  }

  /*
   * determine which memory opcode to use
   */
  if (mem->op[AVR_OP_WRITE_LO]) {
    if (addr & 0x01)
      writeop = mem->op[AVR_OP_WRITE_HI];
    else
      writeop = mem->op[AVR_OP_WRITE_LO];
    caddr = addr / 2;
  }
  else if (mem->op[AVR_OP_LOADPAGE_LO]) {
    if (addr & 0x01)
      writeop = mem->op[AVR_OP_LOADPAGE_HI];
    else
      writeop = mem->op[AVR_OP_LOADPAGE_LO];
    caddr = addr / 2;
  }
  else {
    writeop = mem->op[AVR_OP_WRITE];
    caddr = addr;
  }

  if (writeop == NULL) {
#if DEBUG
    fprintf(stderr, 
            "avr_write_byte(): write not supported for memory type \"%s\"\n",
            mem->desc);
#endif
    return -1;
  }


  pgm->pgm_led(pgm, ON);
  pgm->err_led(pgm, OFF);

  memset(cmd, 0, sizeof(cmd));

  avr_set_bits(writeop, cmd);
  avr_set_addr(writeop, cmd, caddr);
  avr_set_input(writeop, cmd, data);
  pgm->cmd(pgm, cmd, res);

  if (mem->paged) {
    /*
     * in paged addressing, single bytes to be written to the memory
     * page complete immediately, we only need to delay when we commit
     * the whole page via the avr_write_page() routine.
     */
    pgm->pgm_led(pgm, OFF);
    return 0;
  }

  if (readok == 0) {
    /*
     * read operation not supported for this memory type, just wait
     * the max programming time and then return 
     */
    usleep(mem->max_write_delay); /* maximum write delay */
    pgm->pgm_led(pgm, OFF);
    return 0;
  }

  tries = 0;
  ready = 0;
  while (!ready) {

    if ((data == mem->readback[0]) ||
        (data == mem->readback[1])) {
      /* 
       * use an extra long delay when we happen to be writing values
       * used for polled data read-back.  In this case, polling
       * doesn't work, and we need to delay the worst case write time
       * specified for the chip.
       */
      usleep(mem->max_write_delay);
      rc = avr_read_byte(pgm, p, mem, addr, &r);
      if (rc != 0) {
        pgm->pgm_led(pgm, OFF);
        pgm->err_led(pgm, OFF);
        return -5;
      }
    }
    else {
      gettimeofday (&tv, NULL);
      start_time = (tv.tv_sec * 1000000) + tv.tv_usec;
      do {
        /*
         * Do polling, but timeout after max_write_delay.