2 * This file is part of the coreboot project.
4 * Copyright (C) 2006 Jon Dufresne <jon.dufresne@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 #include <sdram_mode.h>
28 /*-----------------------------------------------------------------------------
29 Macros and definitions:
30 -----------------------------------------------------------------------------*/
32 #define VALIDATE_DIMM_COMPATIBILITY
34 /* Debugging macros. */
35 #if CONFIG_DEBUG_RAM_SETUP
36 #define PRINTK_DEBUG(x...) printk(BIOS_DEBUG, x)
37 #define DUMPNORTH() dump_pci_device(NORTHBRIDGE_MMC)
39 #define PRINTK_DEBUG(x...)
43 #define delay() udelay(200)
45 #define VG85X_MODE (SDRAM_BURST_4 | SDRAM_BURST_INTERLEAVED | SDRAM_CAS_2_5)
47 /* DRC[10:8] - Refresh Mode Select (RMS).
48 * 0x0 for Refresh Disabled (Self Refresh)
49 * 0x1 for Refresh interval 15.6 us for 133MHz
50 * 0x2 for Refresh interval 7.8 us for 133MHz
51 * 0x7 for Refresh interval 64 Clocks. (Fast Refresh Mode)
53 #define RAM_COMMAND_REFRESH 0x1
55 /* DRC[6:4] - SDRAM Mode Select (SMS). */
56 #define RAM_COMMAND_SELF_REFRESH 0x0
57 #define RAM_COMMAND_NOP 0x1
58 #define RAM_COMMAND_PRECHARGE 0x2
59 #define RAM_COMMAND_MRS 0x3
60 #define RAM_COMMAND_EMRS 0x4
61 #define RAM_COMMAND_CBR 0x6
62 #define RAM_COMMAND_NORMAL 0x7
64 /* DRC[29] - Initialization Complete (IC). */
65 #define RAM_COMMAND_IC 0x1
72 static const uint32_t refresh_frequency[] = {
73 /* Relative frequency (array value) of each E7501 Refresh Mode Select
74 * (RMS) value (array index)
75 * 0 == least frequent refresh (longest interval between refreshes)
85 0, 2, 3, 1, 0, 0, 0, 4
88 static const uint32_t refresh_rate_map[] = {
89 /* Map the JEDEC spd refresh rates (array index) to i855 Refresh Mode
90 * Select values (array value)
91 * These are all the rates defined by JESD21-C Appendix D, Rev. 1.0
92 * The i855 supports only 15.6 us (1), 7.8 us (2) and
93 * 64 clock (481 ns) (7) refresh.
94 * [0] == 15.625 us -> 15.6 us
95 * [1] == 3.9 us -> 481 ns
96 * [2] == 7.8 us -> 7.8 us
97 * [3] == 31.3 us -> 15.6 us
98 * [4] == 62.5 us -> 15.6 us
99 * [5] == 125 us -> 15.6 us
104 #define MAX_SPD_REFRESH_RATE ((sizeof(refresh_rate_map) / sizeof(uint32_t)) - 1)
106 /*-----------------------------------------------------------------------------
108 -----------------------------------------------------------------------------*/
110 static void die_on_spd_error(int spd_return_value)
112 if (spd_return_value < 0)
113 PRINTK_DEBUG("Error reading SPD info: got %d\n", spd_return_value);
115 if (spd_return_value < 0)
116 die("Error reading SPD info\n");
121 * Calculate the page size for each physical bank of the DIMM:
123 * log2(page size) = (# columns) + log2(data width)
125 * NOTE: Page size is the total number of data bits in a row.
127 * @param dimm_socket_address SMBus address of DIMM socket to interrogate.
128 * @return log2(page size) for each side of the DIMM.
130 static struct dimm_size sdram_spd_get_page_size(u8 dimm_socket_address)
132 uint16_t module_data_width;
134 struct dimm_size pgsz;
140 value = spd_read_byte(dimm_socket_address, SPD_NUM_COLUMNS);
141 die_on_spd_error(value);
143 pgsz.side1 = value & 0xf; // # columns in bank 1
145 /* Get the module data width and convert it to a power of two */
146 value = spd_read_byte(dimm_socket_address, SPD_MODULE_DATA_WIDTH_MSB);
147 die_on_spd_error(value);
149 module_data_width = (value & 0xff) << 8;
151 value = spd_read_byte(dimm_socket_address, SPD_MODULE_DATA_WIDTH_LSB);
152 die_on_spd_error(value);
154 module_data_width |= (value & 0xff);
156 pgsz.side1 += log2(module_data_width);
159 value = spd_read_byte(dimm_socket_address, SPD_NUM_DIMM_BANKS);
160 die_on_spd_error(value);
164 die("Bad SPD value\n");
167 PRINTK_DEBUG("Bad SPD value\n");
170 pgsz.side2 = pgsz.side1; // Assume symmetric banks until we know differently
171 value = spd_read_byte(dimm_socket_address, SPD_NUM_COLUMNS);
172 die_on_spd_error(value);
174 if ((value & 0xf0) != 0) {
176 pgsz.side2 -= value & 0xf; /* Subtract out columns on side 1 */
177 pgsz.side2 += (value >> 4) & 0xf; /* Add in columns on side 2 */
185 * Read the width in bits of each DIMM side's DRAMs via SPD (i.e. 4, 8, 16).
187 * @param dimm_socket_address SMBus address of DIMM socket to interrogate.
188 * @return Width in bits of each DIMM side's DRAMs.
190 static struct dimm_size sdram_spd_get_width(u8 dimm_socket_address)
193 struct dimm_size width;
198 value = spd_read_byte(dimm_socket_address, SPD_PRIMARY_SDRAM_WIDTH);
199 die_on_spd_error(value);
201 width.side1 = value & 0x7f; // Mask off bank 2 flag
204 width.side2 = width.side1 << 1; // Bank 2 exists and is double-width
206 // If bank 2 exists, it's the same width as bank 1
207 value = spd_read_byte(dimm_socket_address, SPD_NUM_DIMM_BANKS);
208 die_on_spd_error(value);
210 #ifdef ROMCC_IF_BUG_FIXED
212 width.side2 = width.side1;
216 width.side2 = width.side1;
229 * Calculate the log base 2 size in bits of both DIMM sides.
231 * log2(# bits) = (# columns) + log2(data width) +
232 * (# rows) + log2(banks per SDRAM)
234 * Note that it might be easier to use SPD byte 31 here, it has the DIMM size
235 * as a multiple of 4MB. The way we do it now we can size both sides of an
238 * @param dimm SMBus address of DIMM socket to interrogate.
239 * @return log2(number of bits) for each side of the DIMM.
241 static struct dimm_size spd_get_dimm_size(unsigned dimm)
245 // Start with log2(page size)
246 struct dimm_size sz = sdram_spd_get_page_size(dimm);
249 value = spd_read_byte(dimm, SPD_NUM_ROWS);
250 die_on_spd_error(value);
252 sz.side1 += value & 0xf;
257 sz.side2 += value >> 4; // Asymmetric
259 sz.side2 += value; // Symmetric
262 value = spd_read_byte(dimm, SPD_NUM_BANKS_PER_SDRAM);
263 die_on_spd_error(value);
275 * Scan for compatible DIMMs.
277 * @return A bitmask indicating which sockets contain a compatible DIMM.
279 static uint8_t spd_get_supported_dimms(void)
282 uint8_t dimm_mask = 0;
284 for (i = 0; i < DIMM_SOCKETS; i++) {
287 #ifdef VALIDATE_DIMM_COMPATIBILITY
288 struct dimm_size page_size;
289 struct dimm_size sdram_width;
294 continue; // No such socket on this mainboard
296 if (spd_read_byte(dimm, SPD_MEMORY_TYPE) != SPD_MEMORY_TYPE_SDRAM_DDR)
299 #ifdef VALIDATE_DIMM_COMPATIBILITY
300 if ((spd_value = spd_read_byte(dimm, SPD_MODULE_VOLTAGE)) != SPD_VOLTAGE_SSTL2) {
301 PRINTK_DEBUG("Skipping DIMM with unsupported voltage: %02x\n", spd_value);
302 continue; // Unsupported voltage
306 // E7501 does not support unregistered DIMMs
307 spd_value = spd_read_byte(dimm, SPD_MODULE_ATTRIBUTES);
308 if (!(spd_value & MODULE_REGISTERED) || (spd_value < 0)) {
309 PRINTK_DEBUG("Skipping unregistered DIMM: %02x\n", spd_value);
314 page_size = sdram_spd_get_page_size(dimm);
315 sdram_width = sdram_spd_get_width(dimm);
317 // Validate DIMM page size
318 // The i855 only supports page sizes of 4, 8, 16 KB per channel
319 // NOTE: 4 KB = 32 Kb = 2^15
320 // 16 KB = 128 Kb = 2^17
322 if ((page_size.side1 < 15) || (page_size.side1 > 17)) {
323 PRINTK_DEBUG("Skipping DIMM with unsupported page size: %d\n", page_size.side1);
327 // If DIMM is double-sided, verify side2 page size
328 if (page_size.side2 != 0) {
329 if ((page_size.side2 < 15) || (page_size.side2 > 17)) {
330 PRINTK_DEBUG("Skipping DIMM with unsupported page size: %d\n", page_size.side2);
334 // Validate SDRAM width
335 // The i855 only supports x8 and x16 devices
336 if ((sdram_width.side1 != 8) && (sdram_width.side1 != 16)) {
337 PRINTK_DEBUG("Skipping DIMM with unsupported width: %d\n", sdram_width.side2);
341 // If DIMM is double-sided, verify side2 width
342 if (sdram_width.side2 != 0) {
343 if ((sdram_width.side2 != 8)
344 && (sdram_width.side2 != 16)) {
345 PRINTK_DEBUG("Skipping DIMM with unsupported width: %d\n", sdram_width.side2);
350 // Made it through all the checks, this DIMM is usable
351 dimm_mask |= (1 << i);
357 /*-----------------------------------------------------------------------------
358 SDRAM configuration functions:
359 -----------------------------------------------------------------------------*/
361 static void do_ram_command(uint8_t command, uint16_t jedec_mode_bits)
365 uint8_t dimm_start_32M_multiple = 0;
366 uint16_t i855_mode_bits = jedec_mode_bits;
368 /* Configure the RAM command. */
369 reg32 = pci_read_config32(NORTHBRIDGE_MMC, DRC);
371 reg32 |= (command << 4);
372 PRINTK_DEBUG(" Sending RAM command 0x%08x\n", reg32);
373 pci_write_config32(NORTHBRIDGE_MMC, DRC, reg32);
375 // RAM_COMMAND_NORMAL is an exception.
376 // It affects only the memory controller and does not need to be "sent" to the DIMMs.
378 if (command != RAM_COMMAND_NORMAL) {
380 // Send the command to all DIMMs by accessing a memory location within each
381 // NOTE: for mode select commands, some of the location address bits
382 // are part of the command
384 // Map JEDEC mode bits to i855
385 if (command == RAM_COMMAND_MRS || command == RAM_COMMAND_EMRS) {
386 /* Host address lines [13:3] map to DIMM address lines [11, 9:0] */
387 i855_mode_bits = ((jedec_mode_bits & 0x800) << (13 - 11)) | ((jedec_mode_bits & 0x3ff) << (12 - 9));
390 for (i = 0; i < (DIMM_SOCKETS * 2); ++i) {
391 uint8_t dimm_end_32M_multiple = pci_read_config8(NORTHBRIDGE_MMC, DRB + i);
392 if (dimm_end_32M_multiple > dimm_start_32M_multiple) {
394 uint32_t dimm_start_address = dimm_start_32M_multiple << 25;
395 PRINTK_DEBUG(" Sending RAM command to 0x%08x\n", dimm_start_address + i855_mode_bits);
396 read32(dimm_start_address + i855_mode_bits);
398 // Set the start of the next DIMM
399 dimm_start_32M_multiple = dimm_end_32M_multiple;
405 static void set_initialize_complete(void)
409 drc_reg = pci_read_config32(NORTHBRIDGE_MMC, DRC);
410 drc_reg |= (1 << 29);
411 pci_write_config32(NORTHBRIDGE_MMC, DRC, drc_reg);
414 static void sdram_enable(void)
418 print_debug("Ram enable 1\n");
423 PRINTK_DEBUG(" NOP\n");
424 do_ram_command(RAM_COMMAND_NOP, 0);
429 /* Pre-charge all banks (at least 200 us after NOP) */
430 PRINTK_DEBUG(" Pre-charging all banks\n");
431 do_ram_command(RAM_COMMAND_PRECHARGE, 0);
436 print_debug("Ram enable 4\n");
437 do_ram_command(RAM_COMMAND_EMRS, SDRAM_EXTMODE_DLL_ENABLE);
442 print_debug("Ram enable 5\n");
443 do_ram_command(RAM_COMMAND_MRS, VG85X_MODE | SDRAM_MODE_DLL_RESET);
445 print_debug("Ram enable 6\n");
446 do_ram_command(RAM_COMMAND_PRECHARGE, 0);
451 /* 8 CBR refreshes (Auto Refresh) */
452 PRINTK_DEBUG(" 8 CBR refreshes\n");
453 for(i = 0; i < 8; i++) {
454 do_ram_command(RAM_COMMAND_CBR, 0);
460 print_debug("Ram enable 8\n");
461 do_ram_command(RAM_COMMAND_MRS, VG85X_MODE | SDRAM_MODE_NORMAL);
463 /* Set GME-M Mode Select bits back to NORMAL operation mode */
464 PRINTK_DEBUG(" Normal operation mode\n");
465 do_ram_command(RAM_COMMAND_NORMAL, 0);
470 print_debug("Ram enable 9\n");
471 set_initialize_complete();
479 print_debug("After configuration:\n");
480 /* dump_pci_devices(); */
483 print_debug("\n\n***** RAM TEST *****\n");
484 ram_check(0, 0xa0000);
485 ram_check(0x100000, 0x40000000);
489 /*-----------------------------------------------------------------------------
490 DIMM-independant configuration functions:
491 -----------------------------------------------------------------------------*/
494 * Set only what I need until it works, then make it figure things out on boot
495 * assumes only one DIMM is populated.
497 static void sdram_set_registers(void)
500 print_debug("Before configuration:\n");
505 static void spd_set_row_attributes(uint8_t dimm_mask)
508 uint16_t row_attributes = 0;
510 for (i = 0; i < DIMM_SOCKETS; i++) {
512 struct dimm_size page_size;
513 struct dimm_size sdram_width;
515 if (!(dimm_mask & (1 << i))) {
516 row_attributes |= 0x77 << (i << 3);
517 continue; // This DIMM not usable
520 // Get the relevant parameters via SPD
521 page_size = sdram_spd_get_page_size(dimm);
522 sdram_width = sdram_spd_get_width(dimm);
524 // Update the DRAM Row Attributes.
525 // Page size is encoded as log2(page size in bits) - log2(2 KB) or 4 KB == 1, 8 KB == 3, 16KB == 3
526 // NOTE: 2 KB = 16 Kb = 2^14
527 row_attributes |= (page_size.side1 - 14) << (i << 3); // Side 1 of each DIMM is an EVEN row
529 if (sdram_width.side2 > 0)
530 row_attributes |= (page_size.side2 - 14) << ((i << 3) + 4); // Side 2 is ODD
532 row_attributes |= 7 << ((i << 3) + 4);
533 /* go to the next DIMM */
536 PRINTK_DEBUG("DRA: %04x\n", row_attributes);
538 /* Write the new row attributes register */
539 pci_write_config16(NORTHBRIDGE_MMC, DRA, row_attributes);
542 static void spd_set_dram_controller_mode(uint8_t dimm_mask)
547 u32 controller_mode = pci_read_config32(NORTHBRIDGE_MMC, DRC);
548 u32 system_refresh_mode = (controller_mode >> 7) & 7;
550 controller_mode |= (1 << 20); // ECC
551 controller_mode |= (1 << 15); // RAS lockout
552 controller_mode |= (1 << 12); // Address Tri-state enable (ADRTRIEN), FIXME: how is this detected?????
553 controller_mode |= (2 << 10); // FIXME: Undocumented, really needed?????
555 for (i = 0; i < DIMM_SOCKETS; i++) {
557 uint32_t dimm_refresh_mode;
561 if (!(dimm_mask & (1 << i))) {
562 continue; // This DIMM not usable
565 // Disable ECC mode if any one of the DIMMs does not support ECC
566 value = spd_read_byte(dimm, SPD_DIMM_CONFIG_TYPE);
567 die_on_spd_error(value);
568 if (value != ERROR_SCHEME_ECC)
569 controller_mode &= ~(3 << 20);
571 value = spd_read_byte(dimm, SPD_REFRESH);
572 die_on_spd_error(value);
573 value &= 0x7f; // Mask off self-refresh bit
574 if (value > MAX_SPD_REFRESH_RATE) {
575 print_err("unsupported refresh rate\n");
578 // Get the appropriate i855 refresh mode for this DIMM
579 dimm_refresh_mode = refresh_rate_map[value];
580 if (dimm_refresh_mode > 7) {
581 print_err("unsupported refresh rate\n");
584 // If this DIMM requires more frequent refresh than others,
585 // update the system setting
586 if (refresh_frequency[dimm_refresh_mode] >
587 refresh_frequency[system_refresh_mode])
588 system_refresh_mode = dimm_refresh_mode;
590 /* FIXME: is this correct? */
591 tRCD = spd_read_byte(dimm, SPD_tRCD);
592 tRP = spd_read_byte(dimm, SPD_tRP);
594 PRINTK_DEBUG(" Disabling RAS lockouk due to tRCD (%d) != tRP (%d)\n", tRCD, tRP);
595 controller_mode &= ~(1 << 15);
598 /* go to the next DIMM */
601 controller_mode &= ~(7 << 7);
602 controller_mode |= (system_refresh_mode << 7);
603 PRINTK_DEBUG("DRC: %08x\n", controller_mode);
605 pci_write_config32(NORTHBRIDGE_MMC, DRC, controller_mode);
608 static void spd_set_dram_timing(uint8_t dimm_mask)
613 // CAS# latency bitmasks in SPD_ACCEPTABLE_CAS_LATENCIES format
614 // NOTE: i82822 supports only 2.0 and 2.5
615 uint32_t system_compatible_cas_latencies = SPD_CAS_LATENCY_2_0 | SPD_CAS_LATENCY_2_5;
616 uint8_t slowest_row_precharge = 0;
617 uint8_t slowest_ras_cas_delay = 0;
618 uint8_t slowest_active_to_precharge_delay = 0;
620 for (i = 0; i < DIMM_SOCKETS; i++) {
623 uint32_t current_cas_latency;
624 uint32_t dimm_compatible_cas_latencies;
625 if (!(dimm_mask & (1 << i)))
626 continue; // This DIMM not usable
628 value = spd_read_byte(dimm, SPD_ACCEPTABLE_CAS_LATENCIES);
629 PRINTK_DEBUG("SPD_ACCEPTABLE_CAS_LATENCIES: %d\n", value);
630 die_on_spd_error(value);
632 dimm_compatible_cas_latencies = value & 0x7f; // Start with all supported by DIMM
633 PRINTK_DEBUG("dimm_compatible_cas_latencies #1: %d\n", dimm_compatible_cas_latencies);
635 current_cas_latency = 1 << log2(dimm_compatible_cas_latencies); // Max supported by DIMM
636 PRINTK_DEBUG("current_cas_latency: %d\n", current_cas_latency);
638 // Can we support the highest CAS# latency?
639 value = spd_read_byte(dimm, SPD_MIN_CYCLE_TIME_AT_CAS_MAX);
640 die_on_spd_error(value);
641 PRINTK_DEBUG("SPD_MIN_CYCLE_TIME_AT_CAS_MAX: %d.%d\n", value >> 4, value & 0xf);
643 // NOTE: At 133 MHz, 1 clock == 7.52 ns
645 // Our bus is too fast for this CAS# latency
646 // Remove it from the bitmask of those supported by the DIMM that are compatible
647 dimm_compatible_cas_latencies &= ~current_cas_latency;
648 PRINTK_DEBUG("dimm_compatible_cas_latencies #2: %d\n", dimm_compatible_cas_latencies);
650 // Can we support the next-highest CAS# latency (max - 0.5)?
652 current_cas_latency >>= 1;
653 if (current_cas_latency != 0) {
654 value = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_2ND);
655 die_on_spd_error(value);
656 PRINTK_DEBUG("SPD_SDRAM_CYCLE_TIME_2ND: %d.%d\n", value >> 4, value & 0xf);
658 dimm_compatible_cas_latencies &= ~current_cas_latency;
659 PRINTK_DEBUG("dimm_compatible_cas_latencies #2: %d\n", dimm_compatible_cas_latencies);
662 // Can we support the next-highest CAS# latency (max - 1.0)?
663 current_cas_latency >>= 1;
664 if (current_cas_latency != 0) {
665 value = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_3RD);
666 PRINTK_DEBUG("SPD_SDRAM_CYCLE_TIME_3RD: %d.%d\n", value >> 4, value & 0xf);
667 die_on_spd_error(value);
669 dimm_compatible_cas_latencies &= ~current_cas_latency;
670 PRINTK_DEBUG("dimm_compatible_cas_latencies #2: %d\n", dimm_compatible_cas_latencies);
673 // Restrict the system to CAS# latencies compatible with this DIMM
674 system_compatible_cas_latencies &= dimm_compatible_cas_latencies;
676 value = spd_read_byte(dimm, SPD_MIN_ROW_PRECHARGE_TIME);
677 die_on_spd_error(value);
678 if (value > slowest_row_precharge)
679 slowest_row_precharge = value;
681 value = spd_read_byte(dimm, SPD_MIN_RAS_TO_CAS_DELAY);
682 die_on_spd_error(value);
683 if (value > slowest_ras_cas_delay)
684 slowest_ras_cas_delay = value;
686 value = spd_read_byte(dimm, SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY);
687 die_on_spd_error(value);
688 if (value > slowest_active_to_precharge_delay)
689 slowest_active_to_precharge_delay = value;
691 /* go to the next DIMM */
693 PRINTK_DEBUG("CAS latency: %d\n", system_compatible_cas_latencies);
695 dram_timing = pci_read_config32(NORTHBRIDGE_MMC, DRT);
696 dram_timing &= ~(DRT_CAS_MASK | DRT_TRP_MASK | DRT_RCD_MASK);
697 PRINTK_DEBUG("DRT: %08x\n", dram_timing);
699 if (system_compatible_cas_latencies & SPD_CAS_LATENCY_2_0) {
700 dram_timing |= DRT_CAS_2_0;
701 } else if (system_compatible_cas_latencies & SPD_CAS_LATENCY_2_5) {
702 dram_timing |= DRT_CAS_2_5;
704 die("No CAS# latencies compatible with all DIMMs!!\n");
706 uint32_t current_cas_latency = dram_timing & DRT_CAS_MASK;
710 PRINTK_DEBUG("slowest_row_precharge: %d.%d\n", slowest_row_precharge >> 2, slowest_row_precharge & 0x3);
711 // i855 supports only 2, 3 or 4 clocks for tRP
712 if (slowest_row_precharge > ((30 << 2)))
713 die("unsupported DIMM tRP"); // > 30.0 ns: 5 or more clocks
714 else if (slowest_row_precharge > ((22 << 2) | (2 << 0)))
715 dram_timing |= DRT_TRP_4; // > 22.5 ns: 4 or more clocks
716 else if (slowest_row_precharge > (15 << 2))
717 dram_timing |= DRT_TRP_3; // > 15.0 ns: 3 clocks
719 dram_timing |= DRT_TRP_2; // <= 15.0 ns: 2 clocks
723 PRINTK_DEBUG("slowest_ras_cas_delay: %d.%d\n", slowest_ras_cas_delay >> 2, slowest_ras_cas_delay & 0x3);
724 // i855 supports only 2, 3 or 4 clocks for tRCD
725 if (slowest_ras_cas_delay > ((30 << 2)))
726 die("unsupported DIMM tRCD"); // > 30.0 ns: 5 or more clocks
727 else if (slowest_ras_cas_delay > ((22 << 2) | (2 << 0)))
728 dram_timing |= DRT_RCD_4; // > 22.5 ns: 4 or more clocks
729 else if (slowest_ras_cas_delay > (15 << 2))
730 dram_timing |= DRT_RCD_3; // > 15.0 ns: 3 clocks
732 dram_timing |= DRT_RCD_2; // <= 15.0 ns: 2 clocks
736 PRINTK_DEBUG("slowest_active_to_precharge_delay: %d\n", slowest_active_to_precharge_delay);
737 // i855 supports only 5, 6, 7 or 8 clocks for tRAS
738 // 5 clocks ~= 37.6 ns, 6 clocks ~= 45.1 ns, 7 clocks ~= 52.6 ns, 8 clocks ~= 60.1 ns
739 if (slowest_active_to_precharge_delay > 60)
740 die("unsupported DIMM tRAS"); // > 52 ns: 8 or more clocks
741 else if (slowest_active_to_precharge_delay > 52)
742 dram_timing |= DRT_TRAS_MIN_8; // 46-52 ns: 7 clocks
743 else if (slowest_active_to_precharge_delay > 45)
744 dram_timing |= DRT_TRAS_MIN_7; // 46-52 ns: 7 clocks
745 else if (slowest_active_to_precharge_delay > 37)
746 dram_timing |= DRT_TRAS_MIN_6; // 38-45 ns: 6 clocks
748 dram_timing |= DRT_TRAS_MIN_5; // < 38 ns: 5 clocks
750 /* FIXME: guess work starts here...
752 * Intel refers to DQ turn-arround values for back to calculate the values,
753 * but i have no idea what this means
757 * Back to Back Read-Write command spacing (DDR, different Rows/Bank)
759 /* Set to a 3 clock back to back read to write turn around.
760 * 2 is a good delay if the CAS latency is 2.0 */
761 dram_timing &= ~(3 << 28);
762 if (current_cas_latency == DRT_CAS_2_0)
763 dram_timing |= (2 << 28); // 2 clocks
765 dram_timing |= (1 << 28); // 3 clocks
768 * Back to Back Read-Write command spacing (DDR, same or different Rows/Bank)
770 dram_timing &= ~(3 << 26);
771 if (current_cas_latency == DRT_CAS_2_0)
772 dram_timing |= (2 << 26); // 5 clocks
774 dram_timing |= (1 << 26); // 6 clocks
777 * Back To Back Read-Read commands spacing (DDR, different Rows):
779 dram_timing &= ~(1 << 25);
780 dram_timing |= (1 << 25); // 3 clocks
782 PRINTK_DEBUG("DRT: %08x\n", dram_timing);
783 pci_write_config32(NORTHBRIDGE_MMC, DRT, dram_timing);
786 static void spd_set_dram_size(uint8_t dimm_mask)
790 uint32_t drb_reg = 0;
792 for (i = 0; i < DIMM_SOCKETS; i++) {
796 if (!(dimm_mask & (1 << i))) {
797 /* fill values even for not present DIMMs */
798 drb_reg |= (total_dram << (i * 16));
799 drb_reg |= (total_dram << ((i * 16) + 8));
801 continue; // This DIMM not usable
803 sz = spd_get_dimm_size(dimm);
805 total_dram += (1 << (sz.side1 - 28));
806 drb_reg |= (total_dram << (i * 16));
808 total_dram += (1 << (sz.side2 - 28));
809 drb_reg |= (total_dram << ((i * 16) + 8));
811 PRINTK_DEBUG("DRB: %08x\n", drb_reg);
812 pci_write_config32(NORTHBRIDGE_MMC, DRB, drb_reg);
816 static void spd_set_dram_pwr_management(void)
820 pwrmg_reg = 0x10f10430;
821 pci_write_config32(NORTHBRIDGE_MMC, PWRMG, pwrmg_reg);
824 static void spd_set_dram_throttle_control(void)
826 uint32_t dtc_reg = 0;
828 /* DDR SDRAM Throttle Mode (TMODE):
829 * 0011 = Both Rank and GMCH Thermal Sensor based throttling is enabled. When the external SO-
830 * DIMM Thermal Sensor is Tripped DDR SDRAM Throttling begins based on the setting in RTT
832 dtc_reg |= (3 << 28);
834 /* Read Counter Based Power Throttle Control (RCTC):
837 dtc_reg |= (0 << 24);
839 /* Write Counter Based Power Throttle Control (WCTC):
842 dtc_reg |= (0 << 20);
844 /* Read Thermal Based Power Throttle Control (RTTC):
847 dtc_reg |= (0xA << 16);
849 /* Write Thermal Based Power Throttle Control (WTTC):
852 dtc_reg |= (0xA << 12);
854 /* Counter Based Throttle Lock (CTLOCK): */
855 dtc_reg |= (0 << 11);
857 /* Thermal Throttle Lock (TTLOCK): */
858 dtc_reg |= (0 << 10);
860 /* Thermal Power Throttle Control fields Enable: */
863 /* High Priority Stream Throttling Enable: */
866 /* Global DDR SDRAM Sampling Window (GDSW): */
868 PRINTK_DEBUG("DTC: %08x\n", dtc_reg);
869 pci_write_config32(NORTHBRIDGE_MMC, DTC, dtc_reg);
872 static void spd_update(u8 reg, u32 new_value)
874 #if CONFIG_DEBUG_RAM_SETUP
875 u32 value1 = pci_read_config32(NORTHBRIDGE_MMC, reg);
877 pci_write_config32(NORTHBRIDGE_MMC, reg, new_value);
878 #if CONFIG_DEBUG_RAM_SETUP
879 u32 value2 = pci_read_config32(NORTHBRIDGE_MMC, reg);
880 PRINTK_DEBUG("update reg %02x, old: %08x, new: %08x, read back: %08x\n", reg, value1, new_value, value2);
884 /* if ram still doesn't work do this function */
885 static void spd_set_undocumented_registers(void)
887 spd_update(0x74, 0x00000001);
888 spd_update(0x78, 0x001fe974);
889 spd_update(0x80, 0x00af0039);
890 spd_update(0x84, 0x0000033c);
891 spd_update(0x88, 0x00000010);
893 spd_update(0xc0, 0x00000003);
896 static void northbridge_set_registers(void)
899 int video_memory = 0;
901 printk(BIOS_DEBUG, "Setting initial Northbridge registers....\n");
903 /* Set the value for Fixed DRAM Hole Control Register */
904 pci_write_config8(NORTHBRIDGE, FDHC, 0x00);
906 /* Set the value for Programable Attribute Map Registers
907 * Ideally, this should be R/W for as many ranges as possible.
909 pci_write_config8(NORTHBRIDGE, PAM0, 0x30);
910 pci_write_config8(NORTHBRIDGE, PAM1, 0x33);
911 pci_write_config8(NORTHBRIDGE, PAM2, 0x33);
912 pci_write_config8(NORTHBRIDGE, PAM3, 0x33);
913 pci_write_config8(NORTHBRIDGE, PAM4, 0x33);
914 pci_write_config8(NORTHBRIDGE, PAM5, 0x33);
915 pci_write_config8(NORTHBRIDGE, PAM6, 0x33);
917 /* Set the value for System Management RAM Control Register */
918 pci_write_config8(NORTHBRIDGE, SMRAM, 0x02);
920 /* Set the value for GMCH Control Register #1 */
921 switch (CONFIG_VIDEO_MB) {
922 case 1: /* 1M of memory */
925 case 4: /* 4M of memory */
928 case 8: /* 8M of memory */
931 case 16: /* 16M of memory */
934 case 32: /* 32M of memory */
937 default: /* No memory */
938 pci_write_config16(NORTHBRIDGE, GMC, pci_read_config16(NORTHBRIDGE, GMC) | 1);
942 value = pci_read_config16(NORTHBRIDGE, GGC);
943 value |= video_memory << 4;
944 if (video_memory == 0) {
948 pci_write_config16(NORTHBRIDGE, GGC, value);
950 /* AGPCMD: disable AGP, Data-Rate: 1x */
951 pci_write_config32(NORTHBRIDGE, AGPCMD, 0x00000001);
953 pci_write_config8(NORTHBRIDGE, AMTT, 0x20);
954 pci_write_config8(NORTHBRIDGE, LPTT, 0x10);
956 printk(BIOS_DEBUG, "Initial Northbridge registers have been set.\n");
959 static void sdram_set_spd_registers(void)
963 PRINTK_DEBUG("Reading SPD data...\n");
965 dimm_mask = spd_get_supported_dimms();
967 if (dimm_mask == 0) {
968 print_debug("No usable memory for this controller\n");
970 PRINTK_DEBUG("DIMM MASK: %02x\n", dimm_mask);
972 spd_set_row_attributes(dimm_mask);
973 spd_set_dram_controller_mode(dimm_mask);
974 spd_set_dram_timing(dimm_mask);
975 spd_set_dram_size(dimm_mask);
976 spd_set_dram_pwr_management();
977 spd_set_dram_throttle_control();
978 spd_set_undocumented_registers();
981 /* Setup Initial Northbridge Registers */
982 northbridge_set_registers();