/* * This file is part of the coreboot project. * * Copyright (C) 2006 Jon Dufresne * * 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; either version 2 of the License, or * (at your option) any later version. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include "i855.h" /*----------------------------------------------------------------------------- Macros and definitions: -----------------------------------------------------------------------------*/ #define VALIDATE_DIMM_COMPATIBILITY /* Debugging macros. */ #if CONFIG_DEBUG_RAM_SETUP #define PRINTK_DEBUG(x...) printk(BIOS_DEBUG, x) #define DUMPNORTH() dump_pci_device(NORTHBRIDGE_MMC) #else #define PRINTK_DEBUG(x...) #define DUMPNORTH() #endif #define delay() udelay(200) #define VG85X_MODE (SDRAM_BURST_4 | SDRAM_BURST_INTERLEAVED | SDRAM_CAS_2_5) /* DRC[10:8] - Refresh Mode Select (RMS). * 0x0 for Refresh Disabled (Self Refresh) * 0x1 for Refresh interval 15.6 us for 133MHz * 0x2 for Refresh interval 7.8 us for 133MHz * 0x7 for Refresh interval 64 Clocks. (Fast Refresh Mode) */ #define RAM_COMMAND_REFRESH 0x1 /* DRC[6:4] - SDRAM Mode Select (SMS). */ #define RAM_COMMAND_SELF_REFRESH 0x0 #define RAM_COMMAND_NOP 0x1 #define RAM_COMMAND_PRECHARGE 0x2 #define RAM_COMMAND_MRS 0x3 #define RAM_COMMAND_EMRS 0x4 #define RAM_COMMAND_CBR 0x6 #define RAM_COMMAND_NORMAL 0x7 /* DRC[29] - Initialization Complete (IC). */ #define RAM_COMMAND_IC 0x1 struct dimm_size { unsigned int side1; unsigned int side2; }; static const uint32_t refresh_frequency[] = { /* Relative frequency (array value) of each E7501 Refresh Mode Select * (RMS) value (array index) * 0 == least frequent refresh (longest interval between refreshes) * [0] disabled -> 0 * [1] 15.6 usec -> 2 * [2] 7.8 usec -> 3 * [3] 64 usec -> 1 * [4] reserved -> 0 * [5] reserved -> 0 * [6] reserved -> 0 * [7] 64 clocks -> 4 */ 0, 2, 3, 1, 0, 0, 0, 4 }; static const uint32_t refresh_rate_map[] = { /* Map the JEDEC spd refresh rates (array index) to i855 Refresh Mode * Select values (array value) * These are all the rates defined by JESD21-C Appendix D, Rev. 1.0 * The i855 supports only 15.6 us (1), 7.8 us (2) and * 64 clock (481 ns) (7) refresh. * [0] == 15.625 us -> 15.6 us * [1] == 3.9 us -> 481 ns * [2] == 7.8 us -> 7.8 us * [3] == 31.3 us -> 15.6 us * [4] == 62.5 us -> 15.6 us * [5] == 125 us -> 15.6 us */ 1, 7, 2, 1, 1, 1 }; #define MAX_SPD_REFRESH_RATE ((sizeof(refresh_rate_map) / sizeof(uint32_t)) - 1) /*----------------------------------------------------------------------------- SPD functions: -----------------------------------------------------------------------------*/ static void die_on_spd_error(int spd_return_value) { if (spd_return_value < 0) PRINTK_DEBUG("Error reading SPD info: got %d\n", spd_return_value); /* if (spd_return_value < 0) die("Error reading SPD info\n"); */ } /** * Calculate the page size for each physical bank of the DIMM: * * log2(page size) = (# columns) + log2(data width) * * NOTE: Page size is the total number of data bits in a row. * * @param dimm_socket_address SMBus address of DIMM socket to interrogate. * @return log2(page size) for each side of the DIMM. */ static struct dimm_size sdram_spd_get_page_size(u8 dimm_socket_address) { uint16_t module_data_width; int value; struct dimm_size pgsz; pgsz.side1 = 0; pgsz.side2 = 0; // Side 1 value = spd_read_byte(dimm_socket_address, SPD_NUM_COLUMNS); die_on_spd_error(value); pgsz.side1 = value & 0xf; // # columns in bank 1 /* Get the module data width and convert it to a power of two */ value = spd_read_byte(dimm_socket_address, SPD_MODULE_DATA_WIDTH_MSB); die_on_spd_error(value); module_data_width = (value & 0xff) << 8; value = spd_read_byte(dimm_socket_address, SPD_MODULE_DATA_WIDTH_LSB); die_on_spd_error(value); module_data_width |= (value & 0xff); pgsz.side1 += log2(module_data_width); /* side two */ value = spd_read_byte(dimm_socket_address, SPD_NUM_DIMM_BANKS); die_on_spd_error(value); /* if (value > 2) die("Bad SPD value\n"); */ if (value > 2) PRINTK_DEBUG("Bad SPD value\n"); if (value == 2) { pgsz.side2 = pgsz.side1; // Assume symmetric banks until we know differently value = spd_read_byte(dimm_socket_address, SPD_NUM_COLUMNS); die_on_spd_error(value); if ((value & 0xf0) != 0) { // Asymmetric banks pgsz.side2 -= value & 0xf; /* Subtract out columns on side 1 */ pgsz.side2 += (value >> 4) & 0xf; /* Add in columns on side 2 */ } } return pgsz; } /** * Read the width in bits of each DIMM side's DRAMs via SPD (i.e. 4, 8, 16). * * @param dimm_socket_address SMBus address of DIMM socket to interrogate. * @return Width in bits of each DIMM side's DRAMs. */ static struct dimm_size sdram_spd_get_width(u8 dimm_socket_address) { int value; struct dimm_size width; width.side1 = 0; width.side2 = 0; value = spd_read_byte(dimm_socket_address, SPD_PRIMARY_SDRAM_WIDTH); die_on_spd_error(value); width.side1 = value & 0x7f; // Mask off bank 2 flag if (value & 0x80) { width.side2 = width.side1 << 1; // Bank 2 exists and is double-width } else { // If bank 2 exists, it's the same width as bank 1 value = spd_read_byte(dimm_socket_address, SPD_NUM_DIMM_BANKS); die_on_spd_error(value); #ifdef ROMCC_IF_BUG_FIXED if (value == 2) width.side2 = width.side1; #else switch (value) { case 2: width.side2 = width.side1; break; default: break; } #endif } return width; } /** * Calculate the log base 2 size in bits of both DIMM sides. * * log2(# bits) = (# columns) + log2(data width) + * (# rows) + log2(banks per SDRAM) * * Note that it might be easier to use SPD byte 31 here, it has the DIMM size * as a multiple of 4MB. The way we do it now we can size both sides of an * asymmetric DIMM. * * @param dimm SMBus address of DIMM socket to interrogate. * @return log2(number of bits) for each side of the DIMM. */ static struct dimm_size spd_get_dimm_size(unsigned dimm) { int value; // Start with log2(page size) struct dimm_size sz = sdram_spd_get_page_size(dimm); if (sz.side1 > 0) { value = spd_read_byte(dimm, SPD_NUM_ROWS); die_on_spd_error(value); sz.side1 += value & 0xf; if (sz.side2 > 0) { // Double-sided DIMM if (value & 0xF0) sz.side2 += value >> 4; // Asymmetric else sz.side2 += value; // Symmetric } value = spd_read_byte(dimm, SPD_NUM_BANKS_PER_SDRAM); die_on_spd_error(value); value = log2(value); sz.side1 += value; if (sz.side2 > 0) sz.side2 += value; } return sz; } /** * Scan for compatible DIMMs. * * @return A bitmask indicating which sockets contain a compatible DIMM. */ static uint8_t spd_get_supported_dimms(void) { int i; uint8_t dimm_mask = 0; for (i = 0; i < DIMM_SOCKETS; i++) { u8 dimm = DIMM0 + i; #ifdef VALIDATE_DIMM_COMPATIBILITY struct dimm_size page_size; struct dimm_size sdram_width; #endif int spd_value; if (dimm == 0) continue; // No such socket on this mainboard if (spd_read_byte(dimm, SPD_MEMORY_TYPE) != SPD_MEMORY_TYPE_SDRAM_DDR) continue; #ifdef VALIDATE_DIMM_COMPATIBILITY if ((spd_value = spd_read_byte(dimm, SPD_MODULE_VOLTAGE)) != SPD_VOLTAGE_SSTL2) { PRINTK_DEBUG("Skipping DIMM with unsupported voltage: %02x\n", spd_value); continue; // Unsupported voltage } /* // E7501 does not support unregistered DIMMs spd_value = spd_read_byte(dimm, SPD_MODULE_ATTRIBUTES); if (!(spd_value & MODULE_REGISTERED) || (spd_value < 0)) { PRINTK_DEBUG("Skipping unregistered DIMM: %02x\n", spd_value); continue; } */ page_size = sdram_spd_get_page_size(dimm); sdram_width = sdram_spd_get_width(dimm); // Validate DIMM page size // The i855 only supports page sizes of 4, 8, 16 KB per channel // NOTE: 4 KB = 32 Kb = 2^15 // 16 KB = 128 Kb = 2^17 if ((page_size.side1 < 15) || (page_size.side1 > 17)) { PRINTK_DEBUG("Skipping DIMM with unsupported page size: %d\n", page_size.side1); continue; } // If DIMM is double-sided, verify side2 page size if (page_size.side2 != 0) { if ((page_size.side2 < 15) || (page_size.side2 > 17)) { PRINTK_DEBUG("Skipping DIMM with unsupported page size: %d\n", page_size.side2); continue; } } // Validate SDRAM width // The i855 only supports x8 and x16 devices if ((sdram_width.side1 != 8) && (sdram_width.side1 != 16)) { PRINTK_DEBUG("Skipping DIMM with unsupported width: %d\n", sdram_width.side2); continue; } // If DIMM is double-sided, verify side2 width if (sdram_width.side2 != 0) { if ((sdram_width.side2 != 8) && (sdram_width.side2 != 16)) { PRINTK_DEBUG("Skipping DIMM with unsupported width: %d\n", sdram_width.side2); continue; } } #endif // Made it through all the checks, this DIMM is usable dimm_mask |= (1 << i); } return dimm_mask; } /*----------------------------------------------------------------------------- SDRAM configuration functions: -----------------------------------------------------------------------------*/ static void do_ram_command(uint8_t command, uint16_t jedec_mode_bits) { int i; u32 reg32; uint8_t dimm_start_32M_multiple = 0; uint16_t i855_mode_bits = jedec_mode_bits; /* Configure the RAM command. */ reg32 = pci_read_config32(NORTHBRIDGE_MMC, DRC); reg32 &= ~(7 << 4); reg32 |= (command << 4); PRINTK_DEBUG(" Sending RAM command 0x%08x\n", reg32); pci_write_config32(NORTHBRIDGE_MMC, DRC, reg32); // RAM_COMMAND_NORMAL is an exception. // It affects only the memory controller and does not need to be "sent" to the DIMMs. if (command != RAM_COMMAND_NORMAL) { // Send the command to all DIMMs by accessing a memory location within each // NOTE: for mode select commands, some of the location address bits // are part of the command // Map JEDEC mode bits to i855 if (command == RAM_COMMAND_MRS || command == RAM_COMMAND_EMRS) { /* Host address lines [13:3] map to DIMM address lines [11, 9:0] */ i855_mode_bits = ((jedec_mode_bits & 0x800) << (13 - 11)) | ((jedec_mode_bits & 0x3ff) << (12 - 9)); } for (i = 0; i < (DIMM_SOCKETS * 2); ++i) { uint8_t dimm_end_32M_multiple = pci_read_config8(NORTHBRIDGE_MMC, DRB + i); if (dimm_end_32M_multiple > dimm_start_32M_multiple) { uint32_t dimm_start_address = dimm_start_32M_multiple << 25; PRINTK_DEBUG(" Sending RAM command to 0x%08x\n", dimm_start_address + i855_mode_bits); read32(dimm_start_address + i855_mode_bits); // Set the start of the next DIMM dimm_start_32M_multiple = dimm_end_32M_multiple; } } } } static void set_initialize_complete(void) { uint32_t drc_reg; drc_reg = pci_read_config32(NORTHBRIDGE_MMC, DRC); drc_reg |= (1 << 29); pci_write_config32(NORTHBRIDGE_MMC, DRC, drc_reg); } static void sdram_enable(void) { int i; print_debug("Ram enable 1\n"); delay(); delay(); /* NOP command */ PRINTK_DEBUG(" NOP\n"); do_ram_command(RAM_COMMAND_NOP, 0); delay(); delay(); delay(); /* Pre-charge all banks (at least 200 us after NOP) */ PRINTK_DEBUG(" Pre-charging all banks\n"); do_ram_command(RAM_COMMAND_PRECHARGE, 0); delay(); delay(); delay(); print_debug("Ram enable 4\n"); do_ram_command(RAM_COMMAND_EMRS, SDRAM_EXTMODE_DLL_ENABLE); delay(); delay(); delay(); print_debug("Ram enable 5\n"); do_ram_command(RAM_COMMAND_MRS, VG85X_MODE | SDRAM_MODE_DLL_RESET); print_debug("Ram enable 6\n"); do_ram_command(RAM_COMMAND_PRECHARGE, 0); delay(); delay(); delay(); /* 8 CBR refreshes (Auto Refresh) */ PRINTK_DEBUG(" 8 CBR refreshes\n"); for(i = 0; i < 8; i++) { do_ram_command(RAM_COMMAND_CBR, 0); delay(); delay(); delay(); } print_debug("Ram enable 8\n"); do_ram_command(RAM_COMMAND_MRS, VG85X_MODE | SDRAM_MODE_NORMAL); /* Set GME-M Mode Select bits back to NORMAL operation mode */ PRINTK_DEBUG(" Normal operation mode\n"); do_ram_command(RAM_COMMAND_NORMAL, 0); delay(); delay(); delay(); print_debug("Ram enable 9\n"); set_initialize_complete(); delay(); delay(); delay(); delay(); delay(); print_debug("After configuration:\n"); /* dump_pci_devices(); */ /* print_debug("\n\n***** RAM TEST *****\n"); ram_check(0, 0xa0000); ram_check(0x100000, 0x40000000); */ } /*----------------------------------------------------------------------------- DIMM-independant configuration functions: -----------------------------------------------------------------------------*/ /** * Set only what I need until it works, then make it figure things out on boot * assumes only one DIMM is populated. */ static void sdram_set_registers(void) { /* print_debug("Before configuration:\n"); dump_pci_devices(); */ } static void spd_set_row_attributes(uint8_t dimm_mask) { int i; uint16_t row_attributes = 0; for (i = 0; i < DIMM_SOCKETS; i++) { u8 dimm = DIMM0 + i; struct dimm_size page_size; struct dimm_size sdram_width; if (!(dimm_mask & (1 << i))) { row_attributes |= 0x77 << (i << 3); continue; // This DIMM not usable } // Get the relevant parameters via SPD page_size = sdram_spd_get_page_size(dimm); sdram_width = sdram_spd_get_width(dimm); // Update the DRAM Row Attributes. // Page size is encoded as log2(page size in bits) - log2(2 KB) or 4 KB == 1, 8 KB == 3, 16KB == 3 // NOTE: 2 KB = 16 Kb = 2^14 row_attributes |= (page_size.side1 - 14) << (i << 3); // Side 1 of each DIMM is an EVEN row if (sdram_width.side2 > 0) row_attributes |= (page_size.side2 - 14) << ((i << 3) + 4); // Side 2 is ODD else row_attributes |= 7 << ((i << 3) + 4); /* go to the next DIMM */ } PRINTK_DEBUG("DRA: %04x\n", row_attributes); /* Write the new row attributes register */ pci_write_config16(NORTHBRIDGE_MMC, DRA, row_attributes); } static void spd_set_dram_controller_mode(uint8_t dimm_mask) { int i; // Initial settings u32 controller_mode = pci_read_config32(NORTHBRIDGE_MMC, DRC); u32 system_refresh_mode = (controller_mode >> 7) & 7; controller_mode |= (1 << 20); // ECC controller_mode |= (1 << 15); // RAS lockout controller_mode |= (1 << 12); // Address Tri-state enable (ADRTRIEN), FIXME: how is this detected????? controller_mode |= (2 << 10); // FIXME: Undocumented, really needed????? for (i = 0; i < DIMM_SOCKETS; i++) { u8 dimm = DIMM0 + i; uint32_t dimm_refresh_mode; int value; u8 tRCD, tRP; if (!(dimm_mask & (1 << i))) { continue; // This DIMM not usable } // Disable ECC mode if any one of the DIMMs does not support ECC value = spd_read_byte(dimm, SPD_DIMM_CONFIG_TYPE); die_on_spd_error(value); if (value != ERROR_SCHEME_ECC) controller_mode &= ~(3 << 20); value = spd_read_byte(dimm, SPD_REFRESH); die_on_spd_error(value); value &= 0x7f; // Mask off self-refresh bit if (value > MAX_SPD_REFRESH_RATE) { print_err("unsupported refresh rate\n"); continue; } // Get the appropriate i855 refresh mode for this DIMM dimm_refresh_mode = refresh_rate_map[value]; if (dimm_refresh_mode > 7) { print_err("unsupported refresh rate\n"); continue; } // If this DIMM requires more frequent refresh than others, // update the system setting if (refresh_frequency[dimm_refresh_mode] > refresh_frequency[system_refresh_mode]) system_refresh_mode = dimm_refresh_mode; /* FIXME: is this correct? */ tRCD = spd_read_byte(dimm, SPD_tRCD); tRP = spd_read_byte(dimm, SPD_tRP); if (tRCD != tRP) { PRINTK_DEBUG(" Disabling RAS lockouk due to tRCD (%d) != tRP (%d)\n", tRCD, tRP); controller_mode &= ~(1 << 15); } /* go to the next DIMM */ } controller_mode &= ~(7 << 7); controller_mode |= (system_refresh_mode << 7); PRINTK_DEBUG("DRC: %08x\n", controller_mode); pci_write_config32(NORTHBRIDGE_MMC, DRC, controller_mode); } static void spd_set_dram_timing(uint8_t dimm_mask) { int i; u32 dram_timing; // CAS# latency bitmasks in SPD_ACCEPTABLE_CAS_LATENCIES format // NOTE: i82822 supports only 2.0 and 2.5 uint32_t system_compatible_cas_latencies = SPD_CAS_LATENCY_2_0 | SPD_CAS_LATENCY_2_5; uint8_t slowest_row_precharge = 0; uint8_t slowest_ras_cas_delay = 0; uint8_t slowest_active_to_precharge_delay = 0; for (i = 0; i < DIMM_SOCKETS; i++) { u8 dimm = DIMM0 + i; int value; uint32_t current_cas_latency; uint32_t dimm_compatible_cas_latencies; if (!(dimm_mask & (1 << i))) continue; // This DIMM not usable value = spd_read_byte(dimm, SPD_ACCEPTABLE_CAS_LATENCIES); PRINTK_DEBUG("SPD_ACCEPTABLE_CAS_LATENCIES: %d\n", value); die_on_spd_error(value); dimm_compatible_cas_latencies = value & 0x7f; // Start with all supported by DIMM PRINTK_DEBUG("dimm_compatible_cas_latencies #1: %d\n", dimm_compatible_cas_latencies); current_cas_latency = 1 << log2(dimm_compatible_cas_latencies); // Max supported by DIMM PRINTK_DEBUG("current_cas_latency: %d\n", current_cas_latency); // Can we support the highest CAS# latency? value = spd_read_byte(dimm, SPD_MIN_CYCLE_TIME_AT_CAS_MAX); die_on_spd_error(value); PRINTK_DEBUG("SPD_MIN_CYCLE_TIME_AT_CAS_MAX: %d.%d\n", value >> 4, value & 0xf); // NOTE: At 133 MHz, 1 clock == 7.52 ns if (value > 0x75) { // Our bus is too fast for this CAS# latency // Remove it from the bitmask of those supported by the DIMM that are compatible dimm_compatible_cas_latencies &= ~current_cas_latency; PRINTK_DEBUG("dimm_compatible_cas_latencies #2: %d\n", dimm_compatible_cas_latencies); } // Can we support the next-highest CAS# latency (max - 0.5)? current_cas_latency >>= 1; if (current_cas_latency != 0) { value = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_2ND); die_on_spd_error(value); PRINTK_DEBUG("SPD_SDRAM_CYCLE_TIME_2ND: %d.%d\n", value >> 4, value & 0xf); if (value > 0x75) { dimm_compatible_cas_latencies &= ~current_cas_latency; PRINTK_DEBUG("dimm_compatible_cas_latencies #2: %d\n", dimm_compatible_cas_latencies); } } // Can we support the next-highest CAS# latency (max - 1.0)? current_cas_latency >>= 1; if (current_cas_latency != 0) { value = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_3RD); PRINTK_DEBUG("SPD_SDRAM_CYCLE_TIME_3RD: %d.%d\n", value >> 4, value & 0xf); die_on_spd_error(value); if (value > 0x75) { dimm_compatible_cas_latencies &= ~current_cas_latency; PRINTK_DEBUG("dimm_compatible_cas_latencies #2: %d\n", dimm_compatible_cas_latencies); } } // Restrict the system to CAS# latencies compatible with this DIMM system_compatible_cas_latencies &= dimm_compatible_cas_latencies; value = spd_read_byte(dimm, SPD_MIN_ROW_PRECHARGE_TIME); die_on_spd_error(value); if (value > slowest_row_precharge) slowest_row_precharge = value; value = spd_read_byte(dimm, SPD_MIN_RAS_TO_CAS_DELAY); die_on_spd_error(value); if (value > slowest_ras_cas_delay) slowest_ras_cas_delay = value; value = spd_read_byte(dimm, SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY); die_on_spd_error(value); if (value > slowest_active_to_precharge_delay) slowest_active_to_precharge_delay = value; /* go to the next DIMM */ } PRINTK_DEBUG("CAS latency: %d\n", system_compatible_cas_latencies); dram_timing = pci_read_config32(NORTHBRIDGE_MMC, DRT); dram_timing &= ~(DRT_CAS_MASK | DRT_TRP_MASK | DRT_RCD_MASK); PRINTK_DEBUG("DRT: %08x\n", dram_timing); if (system_compatible_cas_latencies & SPD_CAS_LATENCY_2_0) { dram_timing |= DRT_CAS_2_0; } else if (system_compatible_cas_latencies & SPD_CAS_LATENCY_2_5) { dram_timing |= DRT_CAS_2_5; } else die("No CAS# latencies compatible with all DIMMs!!\n"); uint32_t current_cas_latency = dram_timing & DRT_CAS_MASK; /* tRP */ PRINTK_DEBUG("slowest_row_precharge: %d.%d\n", slowest_row_precharge >> 2, slowest_row_precharge & 0x3); // i855 supports only 2, 3 or 4 clocks for tRP if (slowest_row_precharge > ((30 << 2))) die("unsupported DIMM tRP"); // > 30.0 ns: 5 or more clocks else if (slowest_row_precharge > ((22 << 2) | (2 << 0))) dram_timing |= DRT_TRP_4; // > 22.5 ns: 4 or more clocks else if (slowest_row_precharge > (15 << 2)) dram_timing |= DRT_TRP_3; // > 15.0 ns: 3 clocks else dram_timing |= DRT_TRP_2; // <= 15.0 ns: 2 clocks /* tRCD */ PRINTK_DEBUG("slowest_ras_cas_delay: %d.%d\n", slowest_ras_cas_delay >> 2, slowest_ras_cas_delay & 0x3); // i855 supports only 2, 3 or 4 clocks for tRCD if (slowest_ras_cas_delay > ((30 << 2))) die("unsupported DIMM tRCD"); // > 30.0 ns: 5 or more clocks else if (slowest_ras_cas_delay > ((22 << 2) | (2 << 0))) dram_timing |= DRT_RCD_4; // > 22.5 ns: 4 or more clocks else if (slowest_ras_cas_delay > (15 << 2)) dram_timing |= DRT_RCD_3; // > 15.0 ns: 3 clocks else dram_timing |= DRT_RCD_2; // <= 15.0 ns: 2 clocks /* tRAS, min */ PRINTK_DEBUG("slowest_active_to_precharge_delay: %d\n", slowest_active_to_precharge_delay); // i855 supports only 5, 6, 7 or 8 clocks for tRAS // 5 clocks ~= 37.6 ns, 6 clocks ~= 45.1 ns, 7 clocks ~= 52.6 ns, 8 clocks ~= 60.1 ns if (slowest_active_to_precharge_delay > 60) die("unsupported DIMM tRAS"); // > 52 ns: 8 or more clocks else if (slowest_active_to_precharge_delay > 52) dram_timing |= DRT_TRAS_MIN_8; // 46-52 ns: 7 clocks else if (slowest_active_to_precharge_delay > 45) dram_timing |= DRT_TRAS_MIN_7; // 46-52 ns: 7 clocks else if (slowest_active_to_precharge_delay > 37) dram_timing |= DRT_TRAS_MIN_6; // 38-45 ns: 6 clocks else dram_timing |= DRT_TRAS_MIN_5; // < 38 ns: 5 clocks /* FIXME: guess work starts here... * * Intel refers to DQ turn-arround values for back to calculate the values, * but i have no idea what this means */ /* * Back to Back Read-Write command spacing (DDR, different Rows/Bank) */ /* Set to a 3 clock back to back read to write turn around. * 2 is a good delay if the CAS latency is 2.0 */ dram_timing &= ~(3 << 28); if (current_cas_latency == DRT_CAS_2_0) dram_timing |= (2 << 28); // 2 clocks else dram_timing |= (1 << 28); // 3 clocks /* * Back to Back Read-Write command spacing (DDR, same or different Rows/Bank) */ dram_timing &= ~(3 << 26); if (current_cas_latency == DRT_CAS_2_0) dram_timing |= (2 << 26); // 5 clocks else dram_timing |= (1 << 26); // 6 clocks /* * Back To Back Read-Read commands spacing (DDR, different Rows): */ dram_timing &= ~(1 << 25); dram_timing |= (1 << 25); // 3 clocks PRINTK_DEBUG("DRT: %08x\n", dram_timing); pci_write_config32(NORTHBRIDGE_MMC, DRT, dram_timing); } static void spd_set_dram_size(uint8_t dimm_mask) { int i; int total_dram = 0; uint32_t drb_reg = 0; for (i = 0; i < DIMM_SOCKETS; i++) { u8 dimm = DIMM0 + i; struct dimm_size sz; if (!(dimm_mask & (1 << i))) { /* fill values even for not present DIMMs */ drb_reg |= (total_dram << (i * 16)); drb_reg |= (total_dram << ((i * 16) + 8)); continue; // This DIMM not usable } sz = spd_get_dimm_size(dimm); total_dram += (1 << (sz.side1 - 28)); drb_reg |= (total_dram << (i * 16)); total_dram += (1 << (sz.side2 - 28)); drb_reg |= (total_dram << ((i * 16) + 8)); } PRINTK_DEBUG("DRB: %08x\n", drb_reg); pci_write_config32(NORTHBRIDGE_MMC, DRB, drb_reg); } static void spd_set_dram_pwr_management(void) { uint32_t pwrmg_reg; pwrmg_reg = 0x10f10430; pci_write_config32(NORTHBRIDGE_MMC, PWRMG, pwrmg_reg); } static void spd_set_dram_throttle_control(void) { uint32_t dtc_reg = 0; /* DDR SDRAM Throttle Mode (TMODE): * 0011 = Both Rank and GMCH Thermal Sensor based throttling is enabled. When the external SO- * DIMM Thermal Sensor is Tripped DDR SDRAM Throttling begins based on the setting in RTT */ dtc_reg |= (3 << 28); /* Read Counter Based Power Throttle Control (RCTC): * 0 = 85% */ dtc_reg |= (0 << 24); /* Write Counter Based Power Throttle Control (WCTC): * 0 = 85% */ dtc_reg |= (0 << 20); /* Read Thermal Based Power Throttle Control (RTTC): * 0xA = 20% */ dtc_reg |= (0xA << 16); /* Write Thermal Based Power Throttle Control (WTTC): * 0xA = 20% */ dtc_reg |= (0xA << 12); /* Counter Based Throttle Lock (CTLOCK): */ dtc_reg |= (0 << 11); /* Thermal Throttle Lock (TTLOCK): */ dtc_reg |= (0 << 10); /* Thermal Power Throttle Control fields Enable: */ dtc_reg |= (1 << 9); /* High Priority Stream Throttling Enable: */ dtc_reg |= (0 << 8); /* Global DDR SDRAM Sampling Window (GDSW): */ dtc_reg |= 0xff; PRINTK_DEBUG("DTC: %08x\n", dtc_reg); pci_write_config32(NORTHBRIDGE_MMC, DTC, dtc_reg); } static void spd_update(u8 reg, u32 new_value) { #if CONFIG_DEBUG_RAM_SETUP u32 value1 = pci_read_config32(NORTHBRIDGE_MMC, reg); #endif pci_write_config32(NORTHBRIDGE_MMC, reg, new_value); #if CONFIG_DEBUG_RAM_SETUP u32 value2 = pci_read_config32(NORTHBRIDGE_MMC, reg); PRINTK_DEBUG("update reg %02x, old: %08x, new: %08x, read back: %08x\n", reg, value1, new_value, value2); #endif } /* if ram still doesn't work do this function */ static void spd_set_undocumented_registers(void) { spd_update(0x74, 0x00000001); spd_update(0x78, 0x001fe974); spd_update(0x80, 0x00af0039); spd_update(0x84, 0x0000033c); spd_update(0x88, 0x00000010); spd_update(0xc0, 0x00000003); } static void northbridge_set_registers(void) { u16 value; int video_memory = 0; printk(BIOS_DEBUG, "Setting initial Northbridge registers....\n"); /* Set the value for Fixed DRAM Hole Control Register */ pci_write_config8(NORTHBRIDGE, FDHC, 0x00); /* Set the value for Programable Attribute Map Registers * Ideally, this should be R/W for as many ranges as possible. */ pci_write_config8(NORTHBRIDGE, PAM0, 0x30); pci_write_config8(NORTHBRIDGE, PAM1, 0x33); pci_write_config8(NORTHBRIDGE, PAM2, 0x33); pci_write_config8(NORTHBRIDGE, PAM3, 0x33); pci_write_config8(NORTHBRIDGE, PAM4, 0x33); pci_write_config8(NORTHBRIDGE, PAM5, 0x33); pci_write_config8(NORTHBRIDGE, PAM6, 0x33); /* Set the value for System Management RAM Control Register */ pci_write_config8(NORTHBRIDGE, SMRAM, 0x02); /* Set the value for GMCH Control Register #1 */ switch (CONFIG_VIDEO_MB) { case 1: /* 1M of memory */ video_memory = 0x1; break; case 4: /* 4M of memory */ video_memory = 0x2; break; case 8: /* 8M of memory */ video_memory = 0x3; break; case 16: /* 16M of memory */ video_memory = 0x4; break; case 32: /* 32M of memory */ video_memory = 0x5; break; default: /* No memory */ pci_write_config16(NORTHBRIDGE, GMC, pci_read_config16(NORTHBRIDGE, GMC) | 1); video_memory = 0x0; } value = pci_read_config16(NORTHBRIDGE, GGC); value |= video_memory << 4; if (video_memory == 0) { value &= ~(1 < 1); } else value |= (1 < 1); pci_write_config16(NORTHBRIDGE, GGC, value); /* AGPCMD: disable AGP, Data-Rate: 1x */ pci_write_config32(NORTHBRIDGE, AGPCMD, 0x00000001); pci_write_config8(NORTHBRIDGE, AMTT, 0x20); pci_write_config8(NORTHBRIDGE, LPTT, 0x10); printk(BIOS_DEBUG, "Initial Northbridge registers have been set.\n"); } static void sdram_set_spd_registers(void) { uint8_t dimm_mask; PRINTK_DEBUG("Reading SPD data...\n"); dimm_mask = spd_get_supported_dimms(); if (dimm_mask == 0) { print_debug("No usable memory for this controller\n"); } else { PRINTK_DEBUG("DIMM MASK: %02x\n", dimm_mask); spd_set_row_attributes(dimm_mask); spd_set_dram_controller_mode(dimm_mask); spd_set_dram_timing(dimm_mask); spd_set_dram_size(dimm_mask); spd_set_dram_pwr_management(); spd_set_dram_throttle_control(); spd_set_undocumented_registers(); } /* Setup Initial Northbridge Registers */ northbridge_set_registers(); }