/*
* This file is part of the coreboot project.
*
* Copyright (C) 2009 One Laptop per Child, Association, Inc.
*
* 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; version 2 of the License.
*
* 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.
*/
void CalcCLAndFreq(DRAM_SYS_ATTR * DramAttr);
/*
Set DRAM Frequency
*/
void DRAMFreqSetting(DRAM_SYS_ATTR * DramAttr)
{
u8 Data = 0;
PRINT_DEBUG_MEM("Dram Frequency setting \r");
//calculate dram frequency using SPD data
CalcCLAndFreq(DramAttr);
//init some Dramc control by Simon Chu slide
//Must use "CPU delay" to make sure VLINK is dis-connect
Data = pci_read_config8(PCI_DEV(0, 0, 7), 0x47);
Data = (u8) (Data | 0x04);
pci_write_config8(PCI_DEV(0, 0, 7), 0x47, Data);
//in order to make sure NB command buffer don`t have pending request(C2P cycle)
//CPU DELAY
WaitMicroSec(20);
//Before Set Dram Frequency, we must set 111 by Simon Chu slide.
Data = pci_read_config8(MEMCTRL, 0x90);
Data = (u8) ((Data & 0xf8) | 7);
pci_write_config8(MEMCTRL, 0x90, Data);
WaitMicroSec(20);
//Set Dram Frequency.
Data = pci_read_config8(MEMCTRL, 0x90);
switch (DramAttr->DramFreq) {
case DIMMFREQ_400:
Data = (u8) ((Data & 0xf8) | 3);
break;
case DIMMFREQ_533:
Data = (u8) ((Data & 0xf8) | 4);
break;
case DIMMFREQ_667:
Data = (u8) ((Data & 0xf8) | 5);
break;
case DIMMFREQ_800:
Data = (u8) ((Data & 0xf8) | 6);
break;
default:
Data = (u8) ((Data & 0xf8) | 1);
}
pci_write_config8(MEMCTRL, 0x90, Data);
//CPU Delay
WaitMicroSec(20);
// Manual reset and adjust DLL when DRAM change frequency
Data = pci_read_config8(MEMCTRL, 0x6B);
Data = (u8) ((Data & 0x2f) | 0xC0);
pci_write_config8(MEMCTRL, 0x6B, Data);
//CPU Delay
WaitMicroSec(20);
Data = pci_read_config8(MEMCTRL, 0x6B);
Data = (u8) (Data | 0x10);
pci_write_config8(MEMCTRL, 0x6B, Data);
//CPU Delay
WaitMicroSec(20);
Data = pci_read_config8(MEMCTRL, 0x6B);
Data = (u8) (Data & 0x3f);
pci_write_config8(MEMCTRL, 0x6B, Data);
//disable V_LINK Auto-Disconnect, or else program may stopped at some place and
//we cannot find the reason
Data = pci_read_config8(PCI_DEV(0, 0, 7), 0x47);
Data = (u8) (Data & 0xFB);
pci_write_config8(PCI_DEV(0, 0, 7), 0x47, Data);
}
/*
calculate CL and dram freq
DDR1
+---+---+---+---+---+---+---+---+
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+---+---+---+---+---+---+---+---+
|TBD| 4 |3.5| 3 |2.5| 2 |1.5| 1 |
+---+---+---+---+---+---+---+---+
DDR2
+---+---+---+---+---+---+---+---+
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
+---+---+---+---+---+---+---+---+
|TBD| 6 | 5 | 4 | 3 | 2 |TBD|TBD|
+---+---+---+---+---+---+---+---+
*/
static const u8 CL_DDR1[7] = { 10, 15, 20, 25, 30, 35, 40 };
static const u8 CL_DDR2[7] = { 0, 0, 20, 30, 40, 50, 60 };
void CalcCLAndFreq(DRAM_SYS_ATTR * DramAttr)
{
u8 AllDimmSupportedCL, Tmp;
u8 CLMask, tmpMask;
u8 SckId, BitId, TmpId;
u16 CycTime, TmpCycTime;
/*1.list the CL value that all DIMM supported */
AllDimmSupportedCL = 0xFF;
if (RAMTYPE_SDRAMDDR2 == DramAttr->DramType)
AllDimmSupportedCL &= 0x7C; /*bit2,3,4,5,6 */
else /*DDR1 */
AllDimmSupportedCL &= 0x7F; /*bit0,1,2,3,4,5,6 */
for (SckId = 0; SckId < MAX_SOCKETS; SckId++) {
if (DramAttr->DimmInfo[SckId].bPresence) { /*all DIMM supported CL */
AllDimmSupportedCL &=
(DramAttr->
DimmInfo[SckId].SPDDataBuf[SPD_SDRAM_CAS_LATENCY]);
}
}
if (!AllDimmSupportedCL) { /*if equal 0, no supported CL */
die("SPD Data Error, Can not get CL !!!! \r");
}
/*Get CL Value */
CLMask = 0x40; /*from Bit6 */
for (BitId = 7; BitId > 0; BitId--) {
if ((AllDimmSupportedCL & CLMask) == CLMask) { /*find the first bit */
if (RAMTYPE_SDRAMDDR2 == DramAttr->DramType)
DramAttr->CL = CL_DDR2[BitId - 1];
else /*DDR1 */
DramAttr->CL = CL_DDR1[BitId - 1];
break;
}
CLMask >>= 1;
}
/*according the CL value calculate the cycle time, for X or X-1 or X-2 */
CycTime = 0;
TmpCycTime = 0;
for (SckId = 0; SckId < MAX_SOCKETS; SckId++) {
if (DramAttr->DimmInfo[SckId].bPresence) {
Tmp =
(DramAttr->
DimmInfo[SckId].SPDDataBuf[SPD_SDRAM_CAS_LATENCY]);
tmpMask = 0x40;
for (TmpId = 7; TmpId > 0; TmpId--) {
if ((Tmp & tmpMask) == tmpMask)
break;
tmpMask >>= 1;
}
if (TmpId - BitId == 0) { /*get Cycle time for X, SPD BYTE9 */
TmpCycTime =
DramAttr->
DimmInfo[SckId].SPDDataBuf
[SPD_SDRAM_TCLK_X];
} else if (TmpId - BitId == 1) { /*get Cycle time for X-1, SPD BYTE23 */
TmpCycTime =
DramAttr->
DimmInfo[SckId].SPDDataBuf
[SPD_SDRAM_TCLK_X_1];
} else if (TmpId - BitId == 2) { /*get cycle time for X-2, SPD BYTE25 */
TmpCycTime =
DramAttr->
DimmInfo[SckId].SPDDataBuf
[SPD_SDRAM_TCLK_X_2];
} else {
//error!!!
}
if (TmpCycTime > CycTime) /*get the most cycle time,there is some problem! */
CycTime = TmpCycTime;
}
}
if (CycTime <= 0) {
//error!
die("Error, cycle time <= 0\n");
}
/* cycle time value
0x25-->2.5ns Freq = 400 DDR800
0x30-->3.0ns Freq = 333 DDR667
0x3D-->3.75ns Freq = 266 DDR533
0x50-->5.0ns Freq = 200 DDR400
0x60-->6.0ns Freq = 166 DDR333
0x75-->7.5ns Freq = 133 DDR266
0xA0-->10.0ns Freq = 100 DDR200
*/
if (CycTime <= 0x25) {
DramAttr->DramFreq = DIMMFREQ_800;
DramAttr->DramCyc = 250;
} else if (CycTime <= 0x30) {
DramAttr->DramFreq = DIMMFREQ_667;
DramAttr->DramCyc = 300;
} else if (CycTime <= 0x3d) {
DramAttr->DramFreq = DIMMFREQ_533;
DramAttr->DramCyc = 375;
} else if (CycTime <= 0x50) {
DramAttr->DramFreq = DIMMFREQ_400;
DramAttr->DramCyc = 500;
} else if (CycTime <= 0x60) {
DramAttr->DramFreq = DIMMFREQ_333;
DramAttr->DramCyc = 600;
} else if (CycTime <= 0x75) {
DramAttr->DramFreq = DIMMFREQ_266;
DramAttr->DramCyc = 750;
} else if (CycTime <= 0xA0) {
DramAttr->DramFreq = DIMMFREQ_200;
DramAttr->DramCyc = 1000;
}
//if set the frequence mannul
PRINT_DEBUG_MEM("Dram Frequency:");
PRINT_DEBUG_MEM_HEX16(DramAttr->DramFreq);
PRINT_DEBUG_MEM(" \r");
}