u-boot/common/ddr_spd.c

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/*
* Copyright 2008 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* Version 2 as published by the Free Software Foundation.
*/
#include <common.h>
#include <ddr_spd.h>
/* used for ddr1 and ddr2 spd */
static int
spd_check(const u8 *buf, u8 spd_rev, u8 spd_cksum)
{
unsigned int cksum = 0;
unsigned int i;
/*
* Check SPD revision supported
* Rev 1.2 or less supported by this code
*/
if (spd_rev > 0x12) {
printf("SPD revision %02X not supported by this code\n",
spd_rev);
return 1;
}
/*
* Calculate checksum
*/
for (i = 0; i < 63; i++) {
cksum += *buf++;
}
cksum &= 0xFF;
if (cksum != spd_cksum) {
printf("SPD checksum unexpected. "
"Checksum in SPD = %02X, computed SPD = %02X\n",
spd_cksum, cksum);
return 1;
}
return 0;
}
unsigned int
ddr1_spd_check(const ddr1_spd_eeprom_t *spd)
{
const u8 *p = (const u8 *)spd;
return spd_check(p, spd->spd_rev, spd->cksum);
}
unsigned int
ddr2_spd_check(const ddr2_spd_eeprom_t *spd)
{
const u8 *p = (const u8 *)spd;
return spd_check(p, spd->spd_rev, spd->cksum);
}