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 #define PRINT_DEBUG(x...) printk(BIOS_DEBUG, x)
42 #define DUMPNORTH() dump_pci_device(NB)
44 #define PRINT_DEBUG(x...)
48 /* SDRAMC[7:5] - SDRAM Mode Select (SMS). */
49 #define RAM_COMMAND_NORMAL 0x0
50 #define RAM_COMMAND_NOP 0x1
51 #define RAM_COMMAND_PRECHARGE 0x2
52 #define RAM_COMMAND_MRS 0x3
53 #define RAM_COMMAND_CBR 0x4
55 /* Map the JEDEC SPD refresh rates (array index) to 440BX refresh rates as
56 * defined in DRAMC[2:0].
58 * [0] == Normal 15.625 us -> 15.6 us
59 * [1] == Reduced(.25X) 3.9 us -> 7.8 ns
60 * [2] == Reduced(.5X) 7.8 us -> 7.8 us
61 * [3] == Extended(2x) 31.3 us -> 31.2 us
62 * [4] == Extended(4x) 62.5 us -> 62.4 us
63 * [5] == Extended(8x) 125 us -> 124.8 us
65 static const uint32_t refresh_rate_map[] = {
69 /* Table format: register, bitmask, value. */
70 static const u8 register_values[] = {
71 /* NBXCFG - NBX Configuration Register
74 * [31:24] SDRAM Row Without ECC
75 * 0 = ECC components are populated in this row
76 * 1 = ECC components are not populated in this row
78 * [18:18] Host Bus Fast Data Ready Enable (HBFDRE)
79 * Assertion of DRAM data on host bus occurs...
80 * 0 = ...one clock after sampling snoop results (default)
81 * 1 = ...on the same clock the snoop result is being sampled
82 * (this mode is faster by one clock cycle)
83 * [17:17] ECC - EDO static Drive mode
84 * 0 = Normal mode (default)
85 * 1 = ECC signals are always driven
86 * [16:16] IDSEL_REDIRECT
87 * 0 = IDSEL1 is allocated to this bridge (default)
88 * 1 = IDSEL7 is allocated to this bridge
89 * [15:15] WSC# Handshake Disable
90 * 1 = Uni-processor mode
91 * 0 = Dual-processor mode with external IOAPIC (default)
92 * [14:14] Intel Reserved
93 * [13:12] Host/DRAM Frequency
98 * [11:11] AGP to PCI Access Enable
101 * [10:10] PCI Agent to Aperture Access Disable
103 * 0 = Enable (default)
104 * [09:09] Aperture Access Global Enable
107 * [08:07] DRAM Data Integrity Mode (DDIM)
111 * 11 = ECC Mode with hardware scrubbing enabled
112 * [06:06] ECC Diagnostic Mode Enable (EDME)
114 * 0 = Normal operation mode (default)
115 * [05:05] MDA Present (MDAP)
116 * Works in conjunction with the VGA_EN bit.
118 * 0 x All VGA cycles are sent to PCI
119 * 1 0 All VGA cycles are sent to AGP
120 * 1 1 All VGA cycles are sent to AGP, except for
121 * cycles in the MDA range.
123 * [03:03] USWC Write Post During I/O Bridge Access Enable (UWPIO)
126 * [02:02] In-Order Queue Depth (IOQD)
127 * 1 = In-order queue = maximum
128 * 0 = A7# is sampled asserted (i.e., 0)
131 NBXCFG + 0, 0x00, 0x0c,
132 // TODO: Bit 15 should be 0 for multiprocessor boards
133 NBXCFG + 1, 0x00, 0x80,
134 NBXCFG + 2, 0x00, 0x00,
135 NBXCFG + 3, 0x00, 0xff,
137 /* DRAMC - DRAM Control Register
141 * [5:5] Module Mode Configuration (MMCONFIG)
142 * The combination of SDRAMPWR and this bit (which is set by an
143 * external strapping option) determine how CKE works.
145 * 0 0 = 3 DIMM, CKE0[5:0] driven
146 * X 1 = 3 DIMM, CKE0 only
147 * 1 0 = 4 DIMM, GCKE only
148 * [4:3] DRAM Type (DT)
151 * 10 = Registered SDRAM
153 * Note: EDO, SDRAM and Registered SDRAM cannot be mixed.
154 * [2:0] DRAM Refresh Rate (DRR)
155 * 000 = Refresh disabled
164 /* Choose SDRAM (not registered), and disable refresh for now. */
168 * PAM[6:0] - Programmable Attribute Map Registers
171 * 0x59 [3:0] Reserved
172 * 0x59 [5:4] 0xF0000 - 0xFFFFF BIOS area
173 * 0x5a [1:0] 0xC0000 - 0xC3FFF ISA add-on BIOS
174 * 0x5a [5:4] 0xC4000 - 0xC7FFF ISA add-on BIOS
175 * 0x5b [1:0] 0xC8000 - 0xCBFFF ISA add-on BIOS
176 * 0x5b [5:4] 0xCC000 - 0xCFFFF ISA add-on BIOS
177 * 0x5c [1:0] 0xD0000 - 0xD3FFF ISA add-on BIOS
178 * 0x5c [5:4] 0xD4000 - 0xD7FFF ISA add-on BIOS
179 * 0x5d [1:0] 0xD8000 - 0xDBFFF ISA add-on BIOS
180 * 0x5d [5:4] 0xDC000 - 0xDFFFF ISA add-on BIOS
181 * 0x5e [1:0] 0xE0000 - 0xE3FFF BIOS entension
182 * 0x5e [5:4] 0xE4000 - 0xE7FFF BIOS entension
183 * 0x5f [1:0] 0xE8000 - 0xEBFFF BIOS entension
184 * 0x5f [5:4] 0xEC000 - 0xEFFFF BIOS entension
187 * 00 = DRAM Disabled (all access goes to memory mapped I/O space)
188 * 01 = Read Only (Reads to DRAM, writes to memory mapped I/O space)
189 * 10 = Write Only (Writes to DRAM, reads to memory mapped I/O space)
190 * 11 = Read/Write (all access goes to DRAM)
194 * Map all legacy regions to RAM (read/write). This is required if
195 * you want to use the RAM area from 768 KB - 1 MB. If the PAM
196 * registers are not set here appropriately, the RAM in that region
197 * will not be accessible, thus a RAM check of it will also fail.
199 * TODO: This was set in sdram_set_spd_registers().
200 * Test if it still works when set here.
210 /* DRB[0:7] - DRAM Row Boundary Registers
213 * An array of 8 byte registers, which hold the ending memory address
214 * assigned to each pair of DIMMs, in 8MB granularity.
216 * 0x60 DRB0 = Total memory in row0 (in 8 MB)
217 * 0x61 DRB1 = Total memory in row0+1 (in 8 MB)
218 * 0x62 DRB2 = Total memory in row0+1+2 (in 8 MB)
219 * 0x63 DRB3 = Total memory in row0+1+2+3 (in 8 MB)
220 * 0x64 DRB4 = Total memory in row0+1+2+3+4 (in 8 MB)
221 * 0x65 DRB5 = Total memory in row0+1+2+3+4+5 (in 8 MB)
222 * 0x66 DRB6 = Total memory in row0+1+2+3+4+5+6 (in 8 MB)
223 * 0x67 DRB7 = Total memory in row0+1+2+3+4+5+6+7 (in 8 MB)
225 /* Set the DRBs to zero for now, this will be fixed later. */
235 /* FDHC - Fixed DRAM Hole Control Register
238 * Controls two fixed DRAM holes: 512 KB - 640 KB and 15 MB - 16 MB.
240 * [7:6] Hole Enable (HEN)
242 * 01 = 512 KB - 640 KB (128 KB)
243 * 10 = 15 MB - 16 MB (1 MB)
247 /* No memory holes. */
250 /* RPS - SDRAM Row Page Size Register
253 * Sets the row page size for SDRAM. For EDO memory, the page
254 * size is fixed at 2 KB.
256 * Bits[1:0] Page Size
262 * RPS bits Corresponding DRB register
263 * [01:00] DRB[0], row 0
264 * [03:02] DRB[1], row 1
265 * [05:04] DRB[2], row 2
266 * [07:06] DRB[3], row 3
267 * [09:08] DRB[4], row 4
268 * [11:10] DRB[5], row 5
269 * [13:12] DRB[6], row 6
270 * [15:14] DRB[7], row 7
272 /* Power on defaults to 2KB. Will be set later. */
273 // RPS + 0, 0x00, 0x00,
274 // RPS + 1, 0x00, 0x00,
276 /* SDRAMC - SDRAM Control Register
280 * [09:08] Idle/Pipeline DRAM Leadoff Timing (IPDLT)
282 * 01 = Add a clock delay to the lead-off clock count
284 * [07:05] SDRAM Mode Select (SMS)
285 * 000 = Normal SDRAM Operation (default)
286 * 001 = NOP Command Enable
287 * 010 = All Banks Precharge Enable
288 * 011 = Mode Register Set Enable
294 * 0 = 3 DIMM configuration
295 * 1 = 4 DIMM configuration
296 * [03:03] Leadoff Command Timing (LCT)
299 * [02:02] CAS# Latency (CL)
300 * 0 = 3 DCLK CAS# latency
301 * 1 = 2 DCLK CAS# latency
302 * [01:01] SDRAM RAS# to CAS# Delay (SRCD)
303 * 0 = 3 clocks between a row activate and a read or write cmd.
304 * 1 = 2 clocks between a row activate and a read or write cmd.
305 * [00:00] SDRAM RAS# Precharge (SRP)
306 * 0 = 3 clocks of RAS# precharge
307 * 1 = 2 clocks of RAS# precharge
309 #if CONFIG_SDRAMPWR_4DIMM
310 SDRAMC + 0, 0x00, 0x10, /* The board has 4 DIMM slots. */
312 SDRAMC + 0, 0x00, 0x00, /* The board has 3 DIMM slots. */
314 SDRAMC + 1, 0x00, 0x00,
316 /* PGPOL - Paging Policy Register
319 * [15:08] Banks per Row (BPR)
320 * Each bit in this field corresponds to one row of the memory
321 * array. Bit 15 corresponds to row 7 while bit 8 corresponds
322 * to row 0. Bits for empty rows are "don't care".
326 * [04:04] Intel Reserved
327 * [03:00] DRAM Idle Timer (DIT)
336 * 1xxx = Infinite (pages are not closed for idle condition)
338 PGPOL + 0, 0x00, 0x00,
339 PGPOL + 1, 0x00, 0xff,
341 /* PMCR - Power Management Control Register
344 * [07:07] Power Down SDRAM Enable (PDSE)
347 * [06:06] ACPI Control Register Enable (SCRE)
349 * 0 = Disable (default)
350 * [05:05] Suspend Refresh Type (SRT)
351 * 1 = Self refresh mode
353 * [04:04] Normal Refresh Enable (NREF_EN)
356 * [03:03] Quick Start Mode (QSTART)
357 * 1 = Quick start mode for the processor is enabled
358 * [02:02] Gated Clock Enable (GCLKEN)
361 * [01:01] AGP Disable (AGP_DIS)
364 * [00:00] CPU reset without PCIRST enable (CRst_En)
368 /* Enable normal refresh and the gated clock. */
369 // TODO: Only do this later?
373 /* Enable SCRR.SRRAEN and let BX choose the SRR. */
374 SCRR + 1, 0x00, 0x10,
377 /*-----------------------------------------------------------------------------
378 SDRAM configuration functions.
379 -----------------------------------------------------------------------------*/
382 * Send the specified RAM command to all DIMMs.
384 * @param command The RAM command to send to the DIMM(s).
386 static void do_ram_command(u32 command)
389 u8 dimm_start, dimm_end;
391 u32 addr, addr_offset;
393 /* Configure the RAM command. */
394 reg16 = pci_read_config16(NB, SDRAMC);
395 reg16 &= 0xff1f; /* Clear bits 7-5. */
396 reg16 |= (u16) (command << 5); /* Write command into bits 7-5. */
397 pci_write_config16(NB, SDRAMC, reg16);
400 * RAM_COMMAND_NORMAL affects only the memory controller and
401 * doesn't need to be "sent" to the DIMMs.
403 if (command == RAM_COMMAND_NORMAL)
406 /* Send the RAM command to each row of memory. */
408 for (i = 0; i < (DIMM_SOCKETS * 2); i++) {
410 caslatency = 3; /* TODO: Dynamically get CAS latency later. */
411 if (command == RAM_COMMAND_MRS) {
413 * MAA[12:11,9:0] must be inverted when sent to DIMM
414 * 2 or 3 (no inversion if sent to DIMM 0 or 1).
416 if ((i >= 0 && i <= 3) && caslatency == 3)
418 if ((i >= 4 && i <= 7) && caslatency == 3)
419 addr_offset = 0x1e28;
420 if ((i >= 0 && i <= 3) && caslatency == 2)
422 if ((i >= 4 && i <= 7) && caslatency == 2)
423 addr_offset = 0x1ea8;
426 dimm_end = pci_read_config8(NB, DRB + i);
428 addr = (dimm_start * 8 * 1024 * 1024) + addr_offset;
429 if (dimm_end > dimm_start) {
431 PRINT_DEBUG(" Sending RAM command 0x%04x to 0x%08x\n",
438 /* Set the start of the next DIMM. */
439 dimm_start = dimm_end;
443 static void set_dram_buffer_strength(void)
445 /* To give some breathing room for romcc,
446 * mbsc0 doubles as drb
447 * mbsc1 doubles as drb1
448 * mbfs0 doubles as i and reg
450 uint8_t mbsc0,mbsc1,mbsc3,mbsc4,mbfs0,mbfs2,fsb;
452 /* Tally how many rows between rows 0-3 and rows 4-7 are populated.
453 * This determines how to program MBFS and MBSC.
459 for (mbfs0 = DRB0; mbfs0 <= DRB7; mbfs0++) {
460 mbsc1 = pci_read_config8(NB, mbfs0);
461 if (mbsc0 != mbsc1) {
471 /* Algorithm bitmap for programming MBSC[39:0] and MBFS[23:0].
473 * The 440BX datasheet says buffer frequency is independent from bus
474 * frequency and mismatch both ways are possible. This is how it is
475 * programmed in the ASUS P2B-LS mainboard.
477 * There are four main conditions to check when programming DRAM buffer
478 * frequency and strength:
480 * a: >2 rows populated across DIMM0,1
481 * b: >2 rows populated across DIMM2,3
482 * c: >4 rows populated across all DIMM slots
484 * 1: NBXCFG[13] strapped as 100MHz, or
485 * 6: NBXCFG[13] strapped as 66MHz
487 * CKE0/FENA ----------------------------------------------------------+
488 * CKE1/GCKE -------------------[ MBFS ]------------------------+|
489 * DQMA/CASA[764320]# ----------[ 0 = 66MHz ]-----------------------+||
490 * DQMB1/CASB1# ----------------[ 1 = 100MHz ]----------------------+|||
491 * DQMB5/CASB5# ---------------------------------------------------+||||
492 * DQMA1/CASA1# --------------------------------------------------+|||||
493 * DQMA5/CASA5# -------------------------------------------------+||||||
494 * CSA0-5#,CSB0-5# ----------------------------------------++++++|||||||
495 * CSA6#/CKE2# -------------------------------------------+|||||||||||||
496 * CSB6#/CKE4# ------------------------------------------+||||||||||||||
497 * CSA7#/CKE3# -----------------------------------------+|||||||||||||||
498 * CSB7#/CKE5# ----------------------------------------+||||||||||||||||
499 * MECC[7:0] #2/#1 (100MHz) -------------------------++|||||||||||||||||
500 * MD[63:0] #2/#1 (100MHz) ------------------------++|||||||||||||||||||
501 * MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB# -+|||||||||||||||||||||
502 * MAA[13:0],WEA#,SRASA#,SCASA# -----------------+||||||||||||||||||||||
503 * Reserved ------------------------------------+|||||||||||||||||||||||
504 * ||||||||||||||||||||||||
505 * 3 32 21 10 0 * 2 21 10 0
506 * 9876543210987654321098765432109876543210 * 321098765432109876543210
507 * a 10------------------------1010---------- * -1---------------11----- a
508 *!a 11------------------------1111---------- * -0---------------00----- !a
509 * b --10--------------------------1010------ * --1----------------11--- b
510 *!b --11--------------------------1111------ * --0----------------00--- !b
511 * c ----------------------------------1100-- * ----------------------1- c
512 *!c ----------------------------------1011-- * ----------------------0- !c
513 * 1 ----1010101000000000000000------------00 * ---11111111111111----1-0 1
514 * 6 ----000000000000000000000010101010----00 * ---1111111111111100000-0 6
515 * | | | | | | | | | | ||||||| | | | | | |
516 * | | | | | | | | | | ||||||| | | | | | +- CKE0/FENA
517 * | | | | | | | | | | ||||||| | | | | +--- CKE1/GCKE
518 * | | | | | | | | | | ||||||| | | | +----- DQMA/CASA[764320]#
519 * | | | | | | | | | | ||||||| | | +------- DQMB1/CASB1#
520 * | | | | | | | | | | ||||||| | +--------- DQMB5/CASB5#
521 * | | | | | | | | | | ||||||| +----------- DQMA1/CASA1#
522 * | | | | | | | | | | ||||||+------------- DQMA5/CASA5#
523 * | | | | | | | | | | ++++++-------------- CSA0-5#,CSB0-5# [ 0=1x;1=2x ]
524 * | | | | | | | | | +--------------------- CSA6#/CKE2#
525 * | | | | | | | | +---[ MBSC ]------ CSB6#/CKE4#
526 * | | | | | | | +-----[ 00 = 1x ]------ CSA7#/CKE3#
527 * | | | | | | +-------[ 01 invalid ]------ CSB7#/CKE5#
528 * | | | | | +---------[ 10 = 2x ]------ MECC[7:0] #1 (2x)
529 * | | | | +-----------[ 11 = 3x ]------ MECC[7:0] #2 (2x)
530 * | | | +--------------------------------- MD[63:0] #1 (2x)
531 * | | +----------------------------------- MD[63:0] #2 (2x)
532 * | +------------------------------------- MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB#
533 * +--------------------------------------- MAA[13:0],WEA#,SRASA#,SCASA#
534 * MBSC[47:40] and MBFS[23] are reserved.
536 * This algorithm is checked against the ASUS P2B-LS (which has
537 * 4 DIMM slots) factory BIOS.
538 * Therefore it assumes a board with 4 slots, and will need testing
539 * on boards with 3 DIMM slots.
545 if (pci_read_config8(NB, NBXCFG + 1) & 0x30) {
558 mbsc4 = mbsc4 | 0x80;
559 mbsc1 = mbsc1 | 0x28;
560 mbfs2 = mbfs2 | 0x40;
561 mbfs0 = mbfs0 | 0x60;
563 mbsc4 = mbsc4 | 0xc0;
565 mbsc1 = mbsc1 | 0x3c;
569 mbsc4 = mbsc4 | 0x20;
570 mbsc1 = mbsc1 | 0x02;
571 mbsc0 = mbsc0 | 0x80;
572 mbfs2 = mbfs2 | 0x20;
573 mbfs0 = mbfs0 | 0x18;
575 mbsc4 = mbsc4 | 0x30;
577 mbsc1 = mbsc1 | 0x03;
578 mbsc0 = mbsc0 | 0xc0;
581 if ((dimm03 + dimm47) > 4) {
582 mbsc0 = mbsc0 | 0x30;
583 mbfs0 = mbfs0 | 0x02;
585 mbsc0 = mbsc0 | 0x2c;
588 pci_write_config8(NB, MBSC + 0, mbsc0);
589 pci_write_config8(NB, MBSC + 1, mbsc1);
590 pci_write_config8(NB, MBSC + 2, 0x00);
591 pci_write_config8(NB, MBSC + 3, mbsc3);
592 pci_write_config8(NB, MBSC + 4, mbsc4);
593 pci_write_config8(NB, MBFS + 0, mbfs0);
594 pci_write_config8(NB, MBFS + 1, 0xff);
595 pci_write_config8(NB, MBFS + 2, mbfs2);
598 /*-----------------------------------------------------------------------------
599 DIMM-independant configuration functions.
600 -----------------------------------------------------------------------------*/
602 static void spd_enable_refresh(void)
607 reg = pci_read_config8(NB, DRAMC);
609 for (i = 0; i < DIMM_SOCKETS; i++) {
610 value = spd_read_byte(DIMM0 + i, SPD_REFRESH);
613 reg = (reg & 0xf8) | refresh_rate_map[(value & 0x7f)];
615 PRINT_DEBUG(" Enabling refresh (DRAMC = 0x%02x) for DIMM %02x\n", reg, i);
618 pci_write_config8(NB, DRAMC, reg);
621 /*-----------------------------------------------------------------------------
623 -----------------------------------------------------------------------------*/
625 void sdram_set_registers(void)
630 PRINT_DEBUG("Northbridge prior to SDRAM init:\n");
633 max = ARRAY_SIZE(register_values);
635 /* Set registers as specified in the register_values[] array. */
636 for (i = 0; i < max; i += 3) {
637 reg = pci_read_config8(NB, register_values[i]);
638 reg &= register_values[i + 1];
639 reg |= register_values[i + 2] & ~(register_values[i + 1]);
640 pci_write_config8(NB, register_values[i], reg);
642 PRINT_DEBUG(" Set register 0x%02x to 0x%02x\n",
643 register_values[i], reg);
653 static struct dimm_size spd_get_dimm_size(unsigned int device)
656 int i, module_density, dimm_banks;
658 module_density = spd_read_byte(device, SPD_DENSITY_OF_EACH_ROW_ON_MODULE);
659 dimm_banks = spd_read_byte(device, SPD_NUM_DIMM_BANKS);
661 /* Find the size of side1. */
662 /* Find the larger value. The larger value is always side1. */
663 for (i = 512; i >= 0; i >>= 1) {
664 if ((module_density & i) == i) {
670 /* Set to 0 in case it's single sided. */
673 /* Test if it's a dual-sided DIMM. */
674 if (dimm_banks > 1) {
675 /* Test if there's a second value. If so it's asymmetrical. */
676 if (module_density != i) {
678 * Find second value, picking up where we left off.
679 * i >>= 1 done initially to make sure we don't get
680 * the same value again.
682 for (i >>= 1; i >= 0; i >>= 1) {
683 if (module_density == (sz.side1 | i)) {
688 /* If not, it's symmetrical. */
695 * SPD byte 31 is the memory size divided by 4 so we
696 * need to muliply by 4 to get the total size.
701 /* It is possible to partially use larger then supported
702 * modules by setting them to a supported size.
705 PRINT_DEBUG("Side1 was %dMB but only 128MB will be used.\n",
710 PRINT_DEBUG("Side2 was %dMB but only 128MB will be used.\n",
719 * Sets DRAM attributes one DIMM at a time, based on SPD data.
720 * Northbridge settings that are set: NBXCFG[31:24], DRB0-DRB7, RPS, DRAMC.
722 static void set_dram_row_attributes(void)
724 int i, dra, drb, col, width, value, rps;
725 u8 bpr; /* Top 8 bits of PGPOL */
726 u8 nbxecc = 0; /* NBXCFG[31:24] */
727 u8 edo, sd, regsd; /* EDO, SDRAM, registered SDRAM */
736 for (i = 0; i < DIMM_SOCKETS; i++) {
742 /* First check if a DIMM is actually present. */
743 value = spd_read_byte(device, SPD_MEMORY_TYPE);
744 /* This is 440BX! We do EDO too! */
745 if (value == SPD_MEMORY_TYPE_EDO
746 || value == SPD_MEMORY_TYPE_SDRAM) {
748 if (value == SPD_MEMORY_TYPE_EDO) {
750 } else if (value == SPD_MEMORY_TYPE_SDRAM) {
753 PRINT_DEBUG("Found DIMM in slot %d\n", i);
756 print_err("Mixing EDO/SDRAM unsupported!\n");
760 /* "DRA" is our RPS for the two rows on this DIMM. */
764 col = spd_read_byte(device, SPD_NUM_COLUMNS);
767 * Is this an ECC DIMM? Actually will be a 2 if so.
768 * TODO: Other register than NBXCFG also needs this
771 value = spd_read_byte(device, SPD_DIMM_CONFIG_TYPE);
774 width = spd_read_byte(device, SPD_MODULE_DATA_WIDTH_LSB);
776 /* Exclude error checking data width from page size calculations */
778 value = spd_read_byte(device,
779 SPD_ERROR_CHECKING_SDRAM_WIDTH);
782 /* Clear top 2 bits to help set up NBXCFG. */
785 /* Without ECC, top 2 bits should be 11. */
789 /* If any installed DIMM is *not* registered, this system cannot be
790 * configured for registered SDRAM.
791 * By registered, only the address and control lines need to be, which
792 * we can tell by reading SPD byte 21, bit 1.
794 value = spd_read_byte(device, SPD_MODULE_ATTRIBUTES);
796 PRINT_DEBUG("DIMM is ");
797 if ((value & MODULE_REGISTERED) == 0) {
801 PRINT_DEBUG("registered\n");
803 /* Calculate page size in bits. */
804 value = ((1 << col) * width);
809 /* Number of banks of DIMM (single or double sided). */
810 value = spd_read_byte(device, SPD_NUM_DIMM_BANKS);
812 /* Once we have dra, col is done and can be reused.
813 * So it's reused for number of banks.
815 col = spd_read_byte(device, SPD_NUM_BANKS_PER_SDRAM);
819 * Second bank of 1-bank DIMMs "doesn't have
820 * ECC" - or anything.
824 } else if (dra == 4) {
826 } else if (dra == 8) {
828 } else if (dra >= 16) {
829 /* Page sizes larger than supported are
830 * set to 8KB to use module partially.
832 PRINT_DEBUG("Page size forced to 8KB.\n");
838 * Sets a flag in PGPOL[BPR] if this DIMM has
843 } else if (value == 2) {
846 } else if (dra == 4) {
847 dra = 0x05; /* 4KB */
848 } else if (dra == 8) {
849 dra = 0x0a; /* 8KB */
850 } else if (dra >= 16) {
852 PRINT_DEBUG("Page size forced to 8KB.\n");
853 dra = 0x0a; /* 8KB */
861 print_err("# of banks of DIMM unsupported!\n");
865 print_err("Page size not supported\n");
870 * 440BX supports asymmetrical dual-sided DIMMs,
871 * but can't handle DIMMs smaller than 8MB per
874 struct dimm_size sz = spd_get_dimm_size(device);
875 if ((sz.side1 < 8)) {
876 print_err("DIMMs smaller than 8MB per side\n"
877 "are not supported on this NB.\n");
881 /* Divide size by 8 to set up the DRB registers. */
882 drb += (sz.side1 / 8);
885 * Build the DRB for the next row in MSB so it gets
886 * placed in DRB[n+1] where it belongs when written
890 drb |= (drb + (sz.side2 / 8)) << 8;
893 PRINT_DEBUG("No DIMM found in slot %d\n", i);
896 /* If there's no DIMM in the slot, set dra to 0x00. */
898 /* Still have to propagate DRB over. */
903 pci_write_config16(NB, DRB + (2 * i), drb);
905 PRINT_DEBUG("DRB has been set to 0x%04x\n", drb);
908 /* Brings the upper DRB back down to be base for
909 * DRB calculations for the next two rows.
913 rps |= (dra & 0x0f) << (i * 4);
916 /* Set paging policy register. */
917 pci_write_config8(NB, PGPOL + 1, bpr);
918 PRINT_DEBUG("PGPOL[BPR] has been set to 0x%02x\n", bpr);
920 /* Set DRAM row page size register. */
921 pci_write_config16(NB, RPS, rps);
922 PRINT_DEBUG("RPS has been set to 0x%04x\n", rps);
925 pci_write_config8(NB, NBXCFG + 3, nbxecc);
926 PRINT_DEBUG("NBXECC[31:24] has been set to 0x%02x\n", nbxecc);
928 /* Set DRAMC[4:3] to proper memory type (EDO/SDRAM/Registered SDRAM). */
930 /* i will be used to set DRAMC[4:3]. */
932 i = 0x10; // Registered SDRAM
939 value = pci_read_config8(NB, DRAMC) & 0xe7;
941 pci_write_config8(NB, DRAMC, value);
942 PRINT_DEBUG("DRAMC has been set to 0x%02x\n", value);
945 void sdram_set_spd_registers(void)
947 /* Setup DRAM row boundary registers and other attributes. */
948 set_dram_row_attributes();
950 /* Setup DRAM buffer strength. */
951 set_dram_buffer_strength();
953 /* TODO: Set PMCR? */
954 // pci_write_config8(NB, PMCR, 0x14);
955 pci_write_config8(NB, PMCR, 0x10);
957 /* TODO: This is for EDO memory only. */
958 pci_write_config8(NB, DRAMT, 0x03);
961 void sdram_enable(void)
965 /* 0. Wait until power/voltages and clocks are stable (200us). */
968 /* 1. Apply NOP. Wait 200 clock cycles (200us should do). */
969 PRINT_DEBUG("RAM Enable 1: Apply NOP\n");
970 do_ram_command(RAM_COMMAND_NOP);
973 /* 2. Precharge all. Wait tRP. */
974 PRINT_DEBUG("RAM Enable 2: Precharge all\n");
975 do_ram_command(RAM_COMMAND_PRECHARGE);
978 /* 3. Perform 8 refresh cycles. Wait tRC each time. */
979 PRINT_DEBUG("RAM Enable 3: CBR\n");
980 for (i = 0; i < 8; i++) {
981 do_ram_command(RAM_COMMAND_CBR);
985 /* 4. Mode register set. Wait two memory cycles. */
986 PRINT_DEBUG("RAM Enable 4: Mode register set\n");
987 do_ram_command(RAM_COMMAND_MRS);
990 /* 5. Normal operation. */
991 PRINT_DEBUG("RAM Enable 5: Normal operation\n");
992 do_ram_command(RAM_COMMAND_NORMAL);
995 /* 6. Finally enable refresh. */
996 PRINT_DEBUG("RAM Enable 6: Enable refresh\n");
997 // pci_write_config8(NB, PMCR, 0x10);
998 spd_enable_refresh();
1001 PRINT_DEBUG("Northbridge following SDRAM init:\n");