2 * This file is part of the coreboot project.
4 * Copyright (C) 2007-2008 Uwe Hermann <uwe@hermann-uwe.de>
5 * Copyright (C) 2010 Keith Hui <buurin@gmail.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
27 #include <arch/romcc_io.h>
28 #include <device/pci_def.h>
29 #include <console/console.h>
33 /*-----------------------------------------------------------------------------
34 Macros and definitions.
35 -----------------------------------------------------------------------------*/
37 #define NB PCI_DEV(0, 0, 0)
39 /* Debugging macros. */
40 #if CONFIG_DEBUG_RAM_SETUP
41 #include "lib/debug.c"
42 #define PRINT_DEBUG(x...) printk(BIOS_DEBUG, x)
43 #define PRINT_DEBUG_HEX8(x) PRINT_DEBUG("%02x", x)
44 #define PRINT_DEBUG_HEX16(x) PRINT_DEBUG("%04x", x)
45 #define PRINT_DEBUG_HEX32(x) PRINT_DEBUG("%08x", x)
46 #define DUMPNORTH() dump_pci_device(NB)
48 #define PRINT_DEBUG(x...)
49 #define PRINT_DEBUG_HEX8(x)
50 #define PRINT_DEBUG_HEX16(x)
51 #define PRINT_DEBUG_HEX32(x)
55 /* SDRAMC[7:5] - SDRAM Mode Select (SMS). */
56 #define RAM_COMMAND_NORMAL 0x0
57 #define RAM_COMMAND_NOP 0x1
58 #define RAM_COMMAND_PRECHARGE 0x2
59 #define RAM_COMMAND_MRS 0x3
60 #define RAM_COMMAND_CBR 0x4
62 /* Map the JEDEC SPD refresh rates (array index) to 440BX refresh rates as
63 * defined in DRAMC[2:0].
65 * [0] == Normal 15.625 us -> 15.6 us
66 * [1] == Reduced(.25X) 3.9 us -> 7.8 ns
67 * [2] == Reduced(.5X) 7.8 us -> 7.8 us
68 * [3] == Extended(2x) 31.3 us -> 31.2 us
69 * [4] == Extended(4x) 62.5 us -> 62.4 us
70 * [5] == Extended(8x) 125 us -> 124.8 us
72 static const uint32_t refresh_rate_map[] = {
76 /* Table format: register, bitmask, value. */
77 static const u8 register_values[] = {
78 /* NBXCFG - NBX Configuration Register
81 * [31:24] SDRAM Row Without ECC
82 * 0 = ECC components are populated in this row
83 * 1 = ECC components are not populated in this row
85 * [18:18] Host Bus Fast Data Ready Enable (HBFDRE)
86 * Assertion of DRAM data on host bus occurs...
87 * 0 = ...one clock after sampling snoop results (default)
88 * 1 = ...on the same clock the snoop result is being sampled
89 * (this mode is faster by one clock cycle)
90 * [17:17] ECC - EDO static Drive mode
91 * 0 = Normal mode (default)
92 * 1 = ECC signals are always driven
93 * [16:16] IDSEL_REDIRECT
94 * 0 = IDSEL1 is allocated to this bridge (default)
95 * 1 = IDSEL7 is allocated to this bridge
96 * [15:15] WSC# Handshake Disable
97 * 1 = Uni-processor mode
98 * 0 = Dual-processor mode with external IOAPIC (default)
99 * [14:14] Intel Reserved
100 * [13:12] Host/DRAM Frequency
105 * [11:11] AGP to PCI Access Enable
108 * [10:10] PCI Agent to Aperture Access Disable
110 * 0 = Enable (default)
111 * [09:09] Aperture Access Global Enable
114 * [08:07] DRAM Data Integrity Mode (DDIM)
118 * 11 = ECC Mode with hardware scrubbing enabled
119 * [06:06] ECC Diagnostic Mode Enable (EDME)
121 * 0 = Normal operation mode (default)
122 * [05:05] MDA Present (MDAP)
123 * Works in conjunction with the VGA_EN bit.
125 * 0 x All VGA cycles are sent to PCI
126 * 1 0 All VGA cycles are sent to AGP
127 * 1 1 All VGA cycles are sent to AGP, except for
128 * cycles in the MDA range.
130 * [03:03] USWC Write Post During I/O Bridge Access Enable (UWPIO)
133 * [02:02] In-Order Queue Depth (IOQD)
134 * 1 = In-order queue = maximum
135 * 0 = A7# is sampled asserted (i.e., 0)
138 NBXCFG + 0, 0x00, 0x0c,
139 // TODO: Bit 15 should be 0 for multiprocessor boards
140 NBXCFG + 1, 0x00, 0x80,
141 NBXCFG + 2, 0x00, 0x00,
142 NBXCFG + 3, 0x00, 0xff,
144 /* DRAMC - DRAM Control Register
148 * [5:5] Module Mode Configuration (MMCONFIG)
149 * The combination of SDRAMPWR and this bit (which is set by an
150 * external strapping option) determine how CKE works.
152 * 0 0 = 3 DIMM, CKE0[5:0] driven
153 * X 1 = 3 DIMM, CKE0 only
154 * 1 0 = 4 DIMM, GCKE only
155 * [4:3] DRAM Type (DT)
158 * 10 = Registered SDRAM
160 * Note: EDO, SDRAM and Registered SDRAM cannot be mixed.
161 * [2:0] DRAM Refresh Rate (DRR)
162 * 000 = Refresh disabled
171 /* Choose SDRAM (not registered), and disable refresh for now. */
175 * PAM[6:0] - Programmable Attribute Map Registers
178 * 0x59 [3:0] Reserved
179 * 0x59 [5:4] 0xF0000 - 0xFFFFF BIOS area
180 * 0x5a [1:0] 0xC0000 - 0xC3FFF ISA add-on BIOS
181 * 0x5a [5:4] 0xC4000 - 0xC7FFF ISA add-on BIOS
182 * 0x5b [1:0] 0xC8000 - 0xCBFFF ISA add-on BIOS
183 * 0x5b [5:4] 0xCC000 - 0xCFFFF ISA add-on BIOS
184 * 0x5c [1:0] 0xD0000 - 0xD3FFF ISA add-on BIOS
185 * 0x5c [5:4] 0xD4000 - 0xD7FFF ISA add-on BIOS
186 * 0x5d [1:0] 0xD8000 - 0xDBFFF ISA add-on BIOS
187 * 0x5d [5:4] 0xDC000 - 0xDFFFF ISA add-on BIOS
188 * 0x5e [1:0] 0xE0000 - 0xE3FFF BIOS entension
189 * 0x5e [5:4] 0xE4000 - 0xE7FFF BIOS entension
190 * 0x5f [1:0] 0xE8000 - 0xEBFFF BIOS entension
191 * 0x5f [5:4] 0xEC000 - 0xEFFFF BIOS entension
194 * 00 = DRAM Disabled (all access goes to memory mapped I/O space)
195 * 01 = Read Only (Reads to DRAM, writes to memory mapped I/O space)
196 * 10 = Write Only (Writes to DRAM, reads to memory mapped I/O space)
197 * 11 = Read/Write (all access goes to DRAM)
201 * Map all legacy regions to RAM (read/write). This is required if
202 * you want to use the RAM area from 768 KB - 1 MB. If the PAM
203 * registers are not set here appropriately, the RAM in that region
204 * will not be accessible, thus a RAM check of it will also fail.
206 * TODO: This was set in sdram_set_spd_registers().
207 * Test if it still works when set here.
217 /* DRB[0:7] - DRAM Row Boundary Registers
220 * An array of 8 byte registers, which hold the ending memory address
221 * assigned to each pair of DIMMs, in 8MB granularity.
223 * 0x60 DRB0 = Total memory in row0 (in 8 MB)
224 * 0x61 DRB1 = Total memory in row0+1 (in 8 MB)
225 * 0x62 DRB2 = Total memory in row0+1+2 (in 8 MB)
226 * 0x63 DRB3 = Total memory in row0+1+2+3 (in 8 MB)
227 * 0x64 DRB4 = Total memory in row0+1+2+3+4 (in 8 MB)
228 * 0x65 DRB5 = Total memory in row0+1+2+3+4+5 (in 8 MB)
229 * 0x66 DRB6 = Total memory in row0+1+2+3+4+5+6 (in 8 MB)
230 * 0x67 DRB7 = Total memory in row0+1+2+3+4+5+6+7 (in 8 MB)
232 /* Set the DRBs to zero for now, this will be fixed later. */
242 /* FDHC - Fixed DRAM Hole Control Register
245 * Controls two fixed DRAM holes: 512 KB - 640 KB and 15 MB - 16 MB.
247 * [7:6] Hole Enable (HEN)
249 * 01 = 512 KB - 640 KB (128 KB)
250 * 10 = 15 MB - 16 MB (1 MB)
254 /* No memory holes. */
257 /* RPS - SDRAM Row Page Size Register
260 * Sets the row page size for SDRAM. For EDO memory, the page
261 * size is fixed at 2 KB.
263 * Bits[1:0] Page Size
269 * RPS bits Corresponding DRB register
270 * [01:00] DRB[0], row 0
271 * [03:02] DRB[1], row 1
272 * [05:04] DRB[2], row 2
273 * [07:06] DRB[3], row 3
274 * [09:08] DRB[4], row 4
275 * [11:10] DRB[5], row 5
276 * [13:12] DRB[6], row 6
277 * [15:14] DRB[7], row 7
279 /* Power on defaults to 2KB. Will be set later. */
280 // RPS + 0, 0x00, 0x00,
281 // RPS + 1, 0x00, 0x00,
283 /* SDRAMC - SDRAM Control Register
287 * [09:08] Idle/Pipeline DRAM Leadoff Timing (IPDLT)
289 * 01 = Add a clock delay to the lead-off clock count
291 * [07:05] SDRAM Mode Select (SMS)
292 * 000 = Normal SDRAM Operation (default)
293 * 001 = NOP Command Enable
294 * 010 = All Banks Precharge Enable
295 * 011 = Mode Register Set Enable
301 * 0 = 3 DIMM configuration
302 * 1 = 4 DIMM configuration
303 * [03:03] Leadoff Command Timing (LCT)
306 * [02:02] CAS# Latency (CL)
307 * 0 = 3 DCLK CAS# latency
308 * 1 = 2 DCLK CAS# latency
309 * [01:01] SDRAM RAS# to CAS# Delay (SRCD)
310 * 0 = 3 clocks between a row activate and a read or write cmd.
311 * 1 = 2 clocks between a row activate and a read or write cmd.
312 * [00:00] SDRAM RAS# Precharge (SRP)
313 * 0 = 3 clocks of RAS# precharge
314 * 1 = 2 clocks of RAS# precharge
316 #if CONFIG_SDRAMPWR_4DIMM
317 SDRAMC + 0, 0x00, 0x10, /* The board has 4 DIMM slots. */
319 SDRAMC + 0, 0x00, 0x00, /* The board has 3 DIMM slots. */
321 SDRAMC + 1, 0x00, 0x00,
323 /* PGPOL - Paging Policy Register
326 * [15:08] Banks per Row (BPR)
327 * Each bit in this field corresponds to one row of the memory
328 * array. Bit 15 corresponds to row 7 while bit 8 corresponds
329 * to row 0. Bits for empty rows are "don't care".
333 * [04:04] Intel Reserved
334 * [03:00] DRAM Idle Timer (DIT)
343 * 1xxx = Infinite (pages are not closed for idle condition)
345 PGPOL + 0, 0x00, 0x00,
346 PGPOL + 1, 0x00, 0xff,
348 /* PMCR - Power Management Control Register
351 * [07:07] Power Down SDRAM Enable (PDSE)
354 * [06:06] ACPI Control Register Enable (SCRE)
356 * 0 = Disable (default)
357 * [05:05] Suspend Refresh Type (SRT)
358 * 1 = Self refresh mode
360 * [04:04] Normal Refresh Enable (NREF_EN)
363 * [03:03] Quick Start Mode (QSTART)
364 * 1 = Quick start mode for the processor is enabled
365 * [02:02] Gated Clock Enable (GCLKEN)
368 * [01:01] AGP Disable (AGP_DIS)
371 * [00:00] CPU reset without PCIRST enable (CRst_En)
375 /* Enable normal refresh and the gated clock. */
376 // TODO: Only do this later?
380 /* Enable SCRR.SRRAEN and let BX choose the SRR. */
381 SCRR + 1, 0x00, 0x10,
384 /*-----------------------------------------------------------------------------
385 SDRAM configuration functions.
386 -----------------------------------------------------------------------------*/
389 * Send the specified RAM command to all DIMMs.
391 * @param command The RAM command to send to the DIMM(s).
393 static void do_ram_command(u32 command)
396 u8 dimm_start, dimm_end;
398 u32 addr, addr_offset;
400 /* Configure the RAM command. */
401 reg16 = pci_read_config16(NB, SDRAMC);
402 reg16 &= 0xff1f; /* Clear bits 7-5. */
403 reg16 |= (u16) (command << 5); /* Write command into bits 7-5. */
404 pci_write_config16(NB, SDRAMC, reg16);
407 * RAM_COMMAND_NORMAL affects only the memory controller and
408 * doesn't need to be "sent" to the DIMMs.
410 if (command == RAM_COMMAND_NORMAL)
413 /* Send the RAM command to each row of memory. */
415 for (i = 0; i < (DIMM_SOCKETS * 2); i++) {
417 caslatency = 3; /* TODO: Dynamically get CAS latency later. */
418 if (command == RAM_COMMAND_MRS) {
420 * MAA[12:11,9:0] must be inverted when sent to DIMM
421 * 2 or 3 (no inversion if sent to DIMM 0 or 1).
423 if ((i >= 0 && i <= 3) && caslatency == 3)
425 if ((i >= 4 && i <= 7) && caslatency == 3)
426 addr_offset = 0x1e28;
427 if ((i >= 0 && i <= 3) && caslatency == 2)
429 if ((i >= 4 && i <= 7) && caslatency == 2)
430 addr_offset = 0x1ea8;
433 dimm_end = pci_read_config8(NB, DRB + i);
435 addr = (dimm_start * 8 * 1024 * 1024) + addr_offset;
436 if (dimm_end > dimm_start) {
438 PRINT_DEBUG(" Sending RAM command 0x");
439 PRINT_DEBUG_HEX16(reg16);
440 PRINT_DEBUG(" to 0x");
441 PRINT_DEBUG_HEX32(addr);
448 /* Set the start of the next DIMM. */
449 dimm_start = dimm_end;
453 static void set_dram_buffer_strength(void)
455 /* To give some breathing room for romcc,
456 * mbsc0 doubles as drb
457 * mbsc1 doubles as drb1
458 * mbfs0 doubles as i and reg
460 uint8_t mbsc0,mbsc1,mbsc3,mbsc4,mbfs0,mbfs2,fsb;
462 /* Tally how many rows between rows 0-3 and rows 4-7 are populated.
463 * This determines how to program MBFS and MBSC.
469 for (mbfs0 = DRB0; mbfs0 <= DRB7; mbfs0++) {
470 mbsc1 = pci_read_config8(NB, mbfs0);
471 if (mbsc0 != mbsc1) {
481 /* Algorithm bitmap for programming MBSC[39:0] and MBFS[23:0].
483 * The 440BX datasheet says buffer frequency is independent from bus
484 * frequency and mismatch both ways are possible. This is how it is
485 * programmed in the ASUS P2B-LS mainboard.
487 * There are four main conditions to check when programming DRAM buffer
488 * frequency and strength:
490 * a: >2 rows populated across DIMM0,1
491 * b: >2 rows populated across DIMM2,3
492 * c: >4 rows populated across all DIMM slots
494 * 1: NBXCFG[13] strapped as 100MHz, or
495 * 6: NBXCFG[13] strapped as 66MHz
497 * CKE0/FENA ----------------------------------------------------------+
498 * CKE1/GCKE -------------------[ MBFS ]------------------------+|
499 * DQMA/CASA[764320]# ----------[ 0 = 66MHz ]-----------------------+||
500 * DQMB1/CASB1# ----------------[ 1 = 100MHz ]----------------------+|||
501 * DQMB5/CASB5# ---------------------------------------------------+||||
502 * DQMA1/CASA1# --------------------------------------------------+|||||
503 * DQMA5/CASA5# -------------------------------------------------+||||||
504 * CSA0-5#,CSB0-5# ----------------------------------------++++++|||||||
505 * CSA6#/CKE2# -------------------------------------------+|||||||||||||
506 * CSB6#/CKE4# ------------------------------------------+||||||||||||||
507 * CSA7#/CKE3# -----------------------------------------+|||||||||||||||
508 * CSB7#/CKE5# ----------------------------------------+||||||||||||||||
509 * MECC[7:0] #2/#1 (100MHz) -------------------------++|||||||||||||||||
510 * MD[63:0] #2/#1 (100MHz) ------------------------++|||||||||||||||||||
511 * MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB# -+|||||||||||||||||||||
512 * MAA[13:0],WEA#,SRASA#,SCASA# -----------------+||||||||||||||||||||||
513 * Reserved ------------------------------------+|||||||||||||||||||||||
514 * ||||||||||||||||||||||||
515 * 3 32 21 10 0 * 2 21 10 0
516 * 9876543210987654321098765432109876543210 * 321098765432109876543210
517 * a 10------------------------1010---------- * -1---------------11----- a
518 *!a 11------------------------1111---------- * -0---------------00----- !a
519 * b --10--------------------------1010------ * --1----------------11--- b
520 *!b --11--------------------------1111------ * --0----------------00--- !b
521 * c ----------------------------------1100-- * ----------------------1- c
522 *!c ----------------------------------1011-- * ----------------------0- !c
523 * 1 ----1010101000000000000000------------00 * ---11111111111111----1-0 1
524 * 6 ----000000000000000000000010101010----00 * ---1111111111111100000-0 6
525 * | | | | | | | | | | ||||||| | | | | | |
526 * | | | | | | | | | | ||||||| | | | | | +- CKE0/FENA
527 * | | | | | | | | | | ||||||| | | | | +--- CKE1/GCKE
528 * | | | | | | | | | | ||||||| | | | +----- DQMA/CASA[764320]#
529 * | | | | | | | | | | ||||||| | | +------- DQMB1/CASB1#
530 * | | | | | | | | | | ||||||| | +--------- DQMB5/CASB5#
531 * | | | | | | | | | | ||||||| +----------- DQMA1/CASA1#
532 * | | | | | | | | | | ||||||+------------- DQMA5/CASA5#
533 * | | | | | | | | | | ++++++-------------- CSA0-5#,CSB0-5# [ 0=1x;1=2x ]
534 * | | | | | | | | | +--------------------- CSA6#/CKE2#
535 * | | | | | | | | +---[ MBSC ]------ CSB6#/CKE4#
536 * | | | | | | | +-----[ 00 = 1x ]------ CSA7#/CKE3#
537 * | | | | | | +-------[ 01 invalid ]------ CSB7#/CKE5#
538 * | | | | | +---------[ 10 = 2x ]------ MECC[7:0] #1 (2x)
539 * | | | | +-----------[ 11 = 3x ]------ MECC[7:0] #2 (2x)
540 * | | | +--------------------------------- MD[63:0] #1 (2x)
541 * | | +----------------------------------- MD[63:0] #2 (2x)
542 * | +------------------------------------- MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB#
543 * +--------------------------------------- MAA[13:0],WEA#,SRASA#,SCASA#
544 * MBSC[47:40] and MBFS[23] are reserved.
546 * This algorithm is checked against the ASUS P2B-LS (which has
547 * 4 DIMM slots) factory BIOS.
548 * Therefore it assumes a board with 4 slots, and will need testing
549 * on boards with 3 DIMM slots.
555 if (pci_read_config8(NB, NBXCFG + 1) & 0x30) {
568 mbsc4 = mbsc4 | 0x80;
569 mbsc1 = mbsc1 | 0x28;
570 mbfs2 = mbfs2 | 0x40;
571 mbfs0 = mbfs0 | 0x60;
573 mbsc4 = mbsc4 | 0xc0;
575 mbsc1 = mbsc1 | 0x3c;
579 mbsc4 = mbsc4 | 0x20;
580 mbsc1 = mbsc1 | 0x02;
581 mbsc0 = mbsc0 | 0x80;
582 mbfs2 = mbfs2 | 0x20;
583 mbfs0 = mbfs0 | 0x18;
585 mbsc4 = mbsc4 | 0x30;
587 mbsc1 = mbsc1 | 0x03;
588 mbsc0 = mbsc0 | 0xc0;
591 if ((dimm03 + dimm47) > 4) {
592 mbsc0 = mbsc0 | 0x30;
593 mbfs0 = mbfs0 | 0x02;
595 mbsc0 = mbsc0 | 0x2c;
598 pci_write_config8(NB, MBSC + 0, mbsc0);
599 pci_write_config8(NB, MBSC + 1, mbsc1);
600 pci_write_config8(NB, MBSC + 2, 0x00);
601 pci_write_config8(NB, MBSC + 3, mbsc3);
602 pci_write_config8(NB, MBSC + 4, mbsc4);
603 pci_write_config8(NB, MBFS + 0, mbfs0);
604 pci_write_config8(NB, MBFS + 1, 0xff);
605 pci_write_config8(NB, MBFS + 2, mbfs2);
608 /*-----------------------------------------------------------------------------
609 DIMM-independant configuration functions.
610 -----------------------------------------------------------------------------*/
612 static void spd_enable_refresh(void)
617 reg = pci_read_config8(NB, DRAMC);
619 for (i = 0; i < DIMM_SOCKETS; i++) {
620 value = spd_read_byte(DIMM0 + i, SPD_REFRESH);
623 reg = (reg & 0xf8) | refresh_rate_map[(value & 0x7f)];
625 PRINT_DEBUG(" Enabling refresh (DRAMC = 0x%02x) for DIMM %02x\n", reg, i);
628 pci_write_config8(NB, DRAMC, reg);
631 /*-----------------------------------------------------------------------------
633 -----------------------------------------------------------------------------*/
635 void sdram_set_registers(void)
640 PRINT_DEBUG("Northbridge prior to SDRAM init:\n");
643 max = ARRAY_SIZE(register_values);
645 /* Set registers as specified in the register_values[] array. */
646 for (i = 0; i < max; i += 3) {
647 reg = pci_read_config8(NB, register_values[i]);
648 reg &= register_values[i + 1];
649 reg |= register_values[i + 2] & ~(register_values[i + 1]);
650 pci_write_config8(NB, register_values[i], reg);
652 PRINT_DEBUG(" Set register 0x");
653 PRINT_DEBUG_HEX8(register_values[i]);
654 PRINT_DEBUG(" to 0x");
655 PRINT_DEBUG_HEX8(reg);
666 static struct dimm_size spd_get_dimm_size(unsigned int device)
669 int i, module_density, dimm_banks;
671 module_density = spd_read_byte(device, SPD_DENSITY_OF_EACH_ROW_ON_MODULE);
672 dimm_banks = spd_read_byte(device, SPD_NUM_DIMM_BANKS);
674 /* Find the size of side1. */
675 /* Find the larger value. The larger value is always side1. */
676 for (i = 512; i >= 0; i >>= 1) {
677 if ((module_density & i) == i) {
683 /* Set to 0 in case it's single sided. */
686 /* Test if it's a dual-sided DIMM. */
687 if (dimm_banks > 1) {
688 /* Test if there's a second value. If so it's asymmetrical. */
689 if (module_density != i) {
691 * Find second value, picking up where we left off.
692 * i >>= 1 done initially to make sure we don't get
693 * the same value again.
695 for (i >>= 1; i >= 0; i >>= 1) {
696 if (module_density == (sz.side1 | i)) {
701 /* If not, it's symmetrical. */
708 * SPD byte 31 is the memory size divided by 4 so we
709 * need to muliply by 4 to get the total size.
714 /* It is possible to partially use larger then supported
715 * modules by setting them to a supported size.
718 PRINT_DEBUG("Side1 was %dMB but only 128MB will be used.\n",
723 PRINT_DEBUG("Side2 was %dMB but only 128MB will be used.\n",
732 * Sets DRAM attributes one DIMM at a time, based on SPD data.
733 * Northbridge settings that are set: NBXCFG[31:24], DRB0-DRB7, RPS, DRAMC.
735 static void set_dram_row_attributes(void)
737 int i, dra, drb, col, width, value, rps, edosd, ecc, nbxecc;
738 u8 bpr; /* Top 8 bits of PGPOL */
746 for (i = 0; i < DIMM_SOCKETS; i++) {
751 /* First check if a DIMM is actually present. */
752 value = spd_read_byte(device, SPD_MEMORY_TYPE);
753 /* This is 440BX! We do EDO too! */
754 if (value == SPD_MEMORY_TYPE_EDO
755 || value == SPD_MEMORY_TYPE_SDRAM) {
757 if (value == SPD_MEMORY_TYPE_EDO) {
759 } else if (value == SPD_MEMORY_TYPE_SDRAM) {
762 PRINT_DEBUG("Found DIMM in slot %d\n", i);
765 print_err("Mixing EDO/SDRAM unsupported!\n");
769 /* "DRA" is our RPS for the two rows on this DIMM. */
773 col = spd_read_byte(device, SPD_NUM_COLUMNS);
776 * Is this an ECC DIMM? Actually will be a 2 if so.
777 * TODO: Other register than NBXCFG also needs this
780 ecc = spd_read_byte(device, SPD_DIMM_CONFIG_TYPE);
783 width = spd_read_byte(device, SPD_MODULE_DATA_WIDTH_LSB);
785 /* Exclude error checking data width from page size calculations */
787 value = spd_read_byte(device,
788 SPD_ERROR_CHECKING_SDRAM_WIDTH);
791 /* Clear top 2 bits to help set up NBXCFG. */
794 /* Without ECC, top 2 bits should be 11. */
798 /* Calculate page size in bits. */
799 value = ((1 << col) * width);
804 /* Number of banks of DIMM (single or double sided). */
805 value = spd_read_byte(device, SPD_NUM_DIMM_BANKS);
807 /* Once we have dra, col is done and can be reused.
808 * So it's reused for number of banks.
810 col = spd_read_byte(device, SPD_NUM_BANKS_PER_SDRAM);
814 * Second bank of 1-bank DIMMs "doesn't have
815 * ECC" - or anything.
820 } else if (dra == 4) {
822 } else if (dra == 8) {
824 } else if (dra >= 16) {
825 /* Page sizes larger than supported are
826 * set to 8KB to use module partially.
828 PRINT_DEBUG("Page size forced to 8KB.\n");
834 * Sets a flag in PGPOL[BPR] if this DIMM has
839 } else if (value == 2) {
842 } else if (dra == 4) {
843 dra = 0x05; /* 4KB */
844 } else if (dra == 8) {
845 dra = 0x0a; /* 8KB */
846 } else if (dra >= 16) {
848 PRINT_DEBUG("Page size forced to 8KB.\n");
849 dra = 0x0a; /* 8KB */
857 print_err("# of banks of DIMM unsupported!\n");
861 print_err("Page size not supported\n");
866 * 440BX supports asymmetrical dual-sided DIMMs,
867 * but can't handle DIMMs smaller than 8MB per
870 struct dimm_size sz = spd_get_dimm_size(device);
871 if ((sz.side1 < 8)) {
872 print_err("DIMMs smaller than 8MB per side\n"
873 "are not supported on this NB.\n");
877 /* Divide size by 8 to set up the DRB registers. */
878 drb += (sz.side1 / 8);
881 * Build the DRB for the next row in MSB so it gets
882 * placed in DRB[n+1] where it belongs when written
886 drb |= (drb + (sz.side2 / 8)) << 8;
889 PRINT_DEBUG("No DIMM found in slot ");
894 /* If there's no DIMM in the slot, set dra to 0x00. */
897 /* Still have to propagate DRB over. */
902 pci_write_config16(NB, DRB + (2 * i), drb);
904 PRINT_DEBUG("DRB has been set to 0x");
905 PRINT_DEBUG_HEX16(drb);
909 /* Brings the upper DRB back down to be base for
910 * DRB calculations for the next two rows.
914 rps |= (dra & 0x0f) << (i * 4);
915 nbxecc = (nbxecc >> 2) | (ecc & 0xc0);
918 /* Set paging policy register. */
919 pci_write_config8(NB, PGPOL + 1, bpr);
920 PRINT_DEBUG("PGPOL[BPR] has been set to 0x%02x\n", bpr);
922 /* Set DRAM row page size register. */
923 pci_write_config16(NB, RPS, rps);
924 PRINT_DEBUG("RPS has been set to 0x%04x\n", rps);
927 pci_write_config8(NB, NBXCFG + 3, nbxecc);
928 PRINT_DEBUG("NBXECC[31:24] has been set to 0x%02x\n", nbxecc);
930 /* Set DRAMC[4:3] to proper memory type (EDO/SDRAM).
931 * TODO: Registered SDRAM support.
936 } else if (edosd & 0x04) {
941 /* edosd is now in the form needed for DRAMC[4:3]. */
942 value = pci_read_config8(NB, DRAMC) & 0xe7;
944 pci_write_config8(NB, DRAMC, value);
945 PRINT_DEBUG("DRAMC has been set to 0x%02x\n", value);
948 void sdram_set_spd_registers(void)
950 /* Setup DRAM row boundary registers and other attributes. */
951 set_dram_row_attributes();
953 /* Setup DRAM buffer strength. */
954 set_dram_buffer_strength();
956 /* TODO: Set PMCR? */
957 // pci_write_config8(NB, PMCR, 0x14);
958 pci_write_config8(NB, PMCR, 0x10);
960 /* TODO: This is for EDO memory only. */
961 pci_write_config8(NB, DRAMT, 0x03);
964 void sdram_enable(void)
968 /* 0. Wait until power/voltages and clocks are stable (200us). */
971 /* 1. Apply NOP. Wait 200 clock cycles (200us should do). */
972 PRINT_DEBUG("RAM Enable 1: Apply NOP\n");
973 do_ram_command(RAM_COMMAND_NOP);
976 /* 2. Precharge all. Wait tRP. */
977 PRINT_DEBUG("RAM Enable 2: Precharge all\n");
978 do_ram_command(RAM_COMMAND_PRECHARGE);
981 /* 3. Perform 8 refresh cycles. Wait tRC each time. */
982 PRINT_DEBUG("RAM Enable 3: CBR\n");
983 for (i = 0; i < 8; i++) {
984 do_ram_command(RAM_COMMAND_CBR);
988 /* 4. Mode register set. Wait two memory cycles. */
989 PRINT_DEBUG("RAM Enable 4: Mode register set\n");
990 do_ram_command(RAM_COMMAND_MRS);
993 /* 5. Normal operation. */
994 PRINT_DEBUG("RAM Enable 5: Normal operation\n");
995 do_ram_command(RAM_COMMAND_NORMAL);
998 /* 6. Finally enable refresh. */
999 PRINT_DEBUG("RAM Enable 6: Enable refresh\n");
1000 // pci_write_config8(NB, PMCR, 0x10);
1001 spd_enable_refresh();
1004 PRINT_DEBUG("Northbridge following SDRAM init:\n");