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Factor out casmap calculation. Gets rid of a warning. 

Signed-off-by: Myles Watson <mylesgw@gmail.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5519 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Myles Watson 2010-04-30 20:36:02 +00:00
parent 95bf86be34
commit 2c32e9902c
1 changed files with 45 additions and 67 deletions
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112
src/northbridge/amd/lx/raminit.c
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@ -238,6 +238,44 @@ static void set_refresh_rate(void)
const uint8_t CASDDR[] = { 5, 5, 2, 6, 3, 7, 4, 0 }; /* 1(1.5), 1.5, 2, 2.5, 3, 3.5, 4, 0 */
static u8 getcasmap(u32 dimm, u16 glspeed)
{
u16 dimm_speed;
u8 spd_byte, casmap, casmap_shift=0;
/************************** DIMM0 **********************************/
casmap = spd_read_byte(dimm, SPD_ACCEPTABLE_CAS_LATENCIES);
if (casmap != 0xFF) {
/* IF -.5 timing is supported, check -.5 timing > GeodeLink */
spd_byte = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_2ND);
if (spd_byte != 0) {
/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
if (dimm_speed >= glspeed) {
casmap_shift = 1; /* -.5 is a shift of 1 */
/* IF -1 timing is supported, check -1 timing > GeodeLink */
spd_byte = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_3RD);
if (spd_byte != 0) {
/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
if (dimm_speed >= glspeed) {
casmap_shift = 2; /* -1 is a shift of 2 */
}
} /* SPD_SDRAM_CYCLE_TIME_3RD (-1) !=0 */
} else {
casmap_shift = 0;
}
} /* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
/* set the casmap based on the shift to limit possible CAS settings */
spd_byte = 31 - __builtin_clz((uint32_t) casmap);
/* just want bits in the lower byte since we have to cast to a 32 */
casmap &= 0xFF << (spd_byte - casmap_shift);
} else { /* No DIMM */
casmap = 0;
}
return casmap;
}
static void setCAS(void)
{
/*;*****************************************************************************
@ -260,82 +298,22 @@ static void setCAS(void)
;* Exit: Set fastest CAS Latency based on GeodeLink speed and SPD information.
;* Destroys: We really use everything !
;*****************************************************************************/
uint16_t glspeed, dimm_speed;
uint8_t spd_byte, casmap0, casmap1, casmap_shift;
uint16_t glspeed;
uint8_t spd_byte, casmap0, casmap1;
msr_t msr;
glspeed = GeodeLinkSpeed();
/************************** DIMM0 **********************************/
casmap0 = spd_read_byte(DIMM0, SPD_ACCEPTABLE_CAS_LATENCIES);
if (casmap0 != 0xFF) {
/* IF -.5 timing is supported, check -.5 timing > GeodeLink */
spd_byte = spd_read_byte(DIMM0, SPD_SDRAM_CYCLE_TIME_2ND);
if (spd_byte != 0) {
/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
if (dimm_speed >= glspeed) {
casmap_shift = 1; /* -.5 is a shift of 1 */
/* IF -1 timing is supported, check -1 timing > GeodeLink */
spd_byte = spd_read_byte(DIMM0, SPD_SDRAM_CYCLE_TIME_3RD);
if (spd_byte != 0) {
/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
if (dimm_speed >= glspeed) {
casmap_shift = 2; /* -1 is a shift of 2 */
}
} /* SPD_SDRAM_CYCLE_TIME_3RD (-1) !=0 */
} else {
casmap_shift = 0;
}
} /* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
/* set the casmap based on the shift to limit possible CAS settings */
spd_byte = 31 - __builtin_clz((uint32_t) casmap0);
/* just want bits in the lower byte since we have to cast to a 32 */
casmap0 &= 0xFF << (spd_byte - casmap_shift);
} else { /* No DIMM */
casmap0 = 0;
}
/************************** DIMM1 **********************************/
casmap1 = spd_read_byte(DIMM1, SPD_ACCEPTABLE_CAS_LATENCIES);
if (casmap1 != 0xFF) {
/* IF -.5 timing is supported, check -.5 timing > GeodeLink */
spd_byte = spd_read_byte(DIMM1, SPD_SDRAM_CYCLE_TIME_2ND);
if (spd_byte != 0) {
/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
if (dimm_speed >= glspeed) {
casmap_shift = 1; /* -.5 is a shift of 1 */
/* IF -1 timing is supported, check -1 timing > GeodeLink */
spd_byte = spd_read_byte(DIMM1, SPD_SDRAM_CYCLE_TIME_3RD);
if (spd_byte != 0) {
/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
if (dimm_speed >= glspeed) {
casmap_shift = 2; /* -1 is a shift of 2 */
}
/* note that the -1 result doesn't need to change the available CAS map */
} /* SPD_SDRAM_CYCLE_TIME_3RD (-1) !=0 */
} else {
casmap_shift = 0;
}
} /* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
/* set the casmap based on the shift to limit possible CAS settings */
spd_byte = 31 - __builtin_clz((uint32_t) casmap1);
/* just want bits in the lower byte since we have to cast to a 32 */
casmap1 &= 0xFF << (spd_byte - casmap_shift);
} else { /* No DIMM */
casmap1 = 0;
}
casmap0 = getcasmap(DIMM0, glspeed);
casmap1 = getcasmap(DIMM1, glspeed);
/********************* CAS_LAT MAP COMPARE ***************************/
if (casmap0 == 0) {
spd_byte = CASDDR[__builtin_ctz((uint32_t) casmap1)];
spd_byte = CASDDR[__builtin_ctz(casmap1)];
} else if (casmap1 == 0) {
spd_byte = CASDDR[__builtin_ctz((uint32_t) casmap0)];
spd_byte = CASDDR[__builtin_ctz(casmap0)];
} else if ((casmap0 &= casmap1)) {
spd_byte = CASDDR[__builtin_ctz((uint32_t) casmap0)];
spd_byte = CASDDR[__builtin_ctz(casmap0)];
} else {
print_emerg("DIMM CAS Latencies not compatible\n");
post_code(ERROR_DIFF_DIMMS);