diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/northbridge/via/vx900/Makefile.inc | 2 | ||||
-rw-r--r-- | src/northbridge/via/vx900/raminit.h | 100 | ||||
-rw-r--r-- | src/northbridge/via/vx900/raminit_ddr3.c | 1682 | ||||
-rw-r--r-- | src/northbridge/via/vx900/vx900.h | 4 |
4 files changed, 1785 insertions, 3 deletions
diff --git a/src/northbridge/via/vx900/Makefile.inc b/src/northbridge/via/vx900/Makefile.inc index 3e0d9c7692..1586c87751 100644 --- a/src/northbridge/via/vx900/Makefile.inc +++ b/src/northbridge/via/vx900/Makefile.inc @@ -21,7 +21,7 @@ romstage-y += pci_util.c romstage-y += early_smbus.c romstage-y += early_vx900.c romstage-y += early_host_bus_ctl.c -#romstage-y += raminit_ddr3.c +romstage-y += raminit_ddr3.c romstage-y += ./../../../device/dram/ddr3.c romstage-y += ./../../../southbridge/via/common/early_smbus_delay.c romstage-y += ./../../../southbridge/via/common/early_smbus_is_busy.c diff --git a/src/northbridge/via/vx900/raminit.h b/src/northbridge/via/vx900/raminit.h new file mode 100644 index 0000000000..c599c0fee8 --- /dev/null +++ b/src/northbridge/via/vx900/raminit.h @@ -0,0 +1,100 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2011 Alexandru Gagniuc <mr.nuke.me@gmail.com> + * + * 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, see <http://www.gnu.org/licenses/>. + */ + +#ifndef RAMINIT_VX900_H +#define RAMINIT_VX900_H + +#include <device/dram/ddr3.h> +#include "vx900.h" + +#define SPD_END_LIST 0xff + +typedef struct dimm_layout_st +{ + /* The address of the DIMM on the SMBUS * + * 0xFF to terminate the array*/ + u8 spd_addr[VX900_MAX_DIMM_SLOTS + 1]; +} dimm_layout; + +typedef struct dimm_info_st +{ + dimm_attr dimm[VX900_MAX_DIMM_SLOTS]; +} dimm_info; + +typedef struct mem_rank_st { + u16 start_addr; + u16 end_addr; +} mem_rank; + +typedef struct rank_layout_st { + u32 phys_rank_size_mb[VX900_MAX_MEM_RANKS]; + mem_rank virt[VX900_MAX_MEM_RANKS]; + dimm_flags_t flags[VX900_MAX_MEM_RANKS]; +} rank_layout; + +typedef struct pci_reg8_st { + u8 addr; + u8 val; +} pci_reg8; + +typedef u8 timing_dly[8]; + +typedef struct delay_range_st { + timing_dly low; + timing_dly avg; + timing_dly high; +} delay_range; + +typedef struct vx900_delay_calib_st { + delay_range rx_dq_cr; + delay_range rx_dqs; + /* Transmit delays are calibrated for each dimm */ + delay_range tx_dq[VX900_MAX_DIMM_SLOTS]; + delay_range tx_dqs[VX900_MAX_DIMM_SLOTS]; +} vx900_delay_calib; + +typedef struct ramctr_timing_st { + enum spd_memory_type dram_type; + u16 cas_supported; + /* tLatencies are in units of ns, scaled by x256 */ + u32 tCK; + u32 tAA; + u32 tWR; + u32 tRCD; + u32 tRRD; + u32 tRP; + u32 tRAS; + u32 tRC; + u32 tRFC; + u32 tWTR; + u32 tRTP; + u32 tFAW; + /* Latencies in terms of clock cycles + * They are saved separately as they are needed for DRAM MRS commands*/ + u8 CAS; /* CAS read latency */ + u8 CWL; /* CAS write latency */ + u8 WR; /* write recovery time */ + /* Number of dimms currently connected */ + u8 n_dimms; + +} ramctr_timing; + +void vx900_init_dram_ddr3(const dimm_layout *dimms); + +#endif /* RAMINIT_VX900_H */ diff --git a/src/northbridge/via/vx900/raminit_ddr3.c b/src/northbridge/via/vx900/raminit_ddr3.c new file mode 100644 index 0000000000..05c3edc67c --- /dev/null +++ b/src/northbridge/via/vx900/raminit_ddr3.c @@ -0,0 +1,1682 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2011-2012 Alexandru Gagniuc <mr.nuke.me@gmail.com> + * + * 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, see <http://www.gnu.org/licenses/>. + */ + +#include "early_vx900.h" +#include "raminit.h" +#include <arch/io.h> +#include <arch/io.h> +#include <console/console.h> +#include <device/pci_ids.h> +#include <delay.h> +#include <lib.h> +#include <string.h> + +/** + * @file raminit_ddr3.c + * + * \brief DDR3 initialization for VIA VX900 chipset + * + * Rather than explain the DDR3 init algorithm, it is better to focus on what + * works and what doesn't. Familiarity with the DDR3 spec does not hurt. + * + * 1 DIMMs and 2 DIMMs with one rank each works. + * 1 rank DIMM with 2 rank DIMM works, but the odd ranks are disabled. + * (2) 2-rank DIMMs will not work. + * + * It is not yet clear if odd ranks do not work because of faulty timing + * calibration, or a misconfiguration of the MCU. I have seen this with DIMMS + * which mirror pins on the odd rank. That could also be the issue. + * + * The capture window is not calibrated, but preset. Whether that preset is + * universal or frequency dependent, and whether it is board-specific or not is + * not yet clear. @see vx900_dram_calibrate_recieve_delays(). + * + * 4GBit and 8GBit modules may not work. This is untested. Modules with 11 + * column address bits are not tested. @see vx900_dram_map_row_col_bank() + * + * Everything else should be in a more or less usable state. FIXME s are placed + * all over as a reminder that either something really needs fixing, or as a + * reminder to double-check. + */ + +/* Map BA0 <-> A17, BA1 <-> A18 */ +/* Map BA2 <-> A19, RA0/RA1 must not overlap BA[0:2] */ +#define VX900_MRS_MA_MAP 0x4b33 /* MA Pin Mapping for MRS commands */ +#define VX900_CALIB_MA_MAP 0x5911 /* MA Pin mapping for calibrations */ + +/* + * Registers 0x78 -> 0x7f contain the calibration settings for DRAM IO timing + * The dataset in these registers is selected from 0x70. + * Once the correct dataset is selected the delays can be altered. + * delay_type refers to TxDQS, TxDQ, RxDQS, or RxCR + * bound refers to either manual, average, upper bound, or lower bound + */ +#define CALIB_TxDQS 0 +#define CALIB_TxDQ 1 +#define CALIB_RxDQS 2 +#define CALIB_RxDQ_CR 3 + +#define CALIB_AVERAGE 0 +#define CALIB_LOWER 1 +#define CALIB_UPPER 2 +#define CALIB_MANUAL 4 /* We want this & 3 to overflow to 0 */ + +static void vx900_delay_calib_mode_select(u8 delay_type, u8 bound) +{ + /* Which calibration setting */ + u8 reg8 = (delay_type & 0x03) << 2; + /* Upper, lower, average, or manual setting */ + reg8 |= (bound & 0x03); + pci_write_config8(MCU, 0x70, reg8); +} + +/* + * The vendor BIOS does something similar to vx900_delay_calib_mode_select(), + * then reads or write a byte, and repeats the process for all 8 bytes. This is + * annoyingly inefficient, and we can achieve the same result in a much more + * elegant manner. + */ +static void vx900_read_0x78_0x7f(timing_dly dly) +{ + *((u32 *) (&(dly[0]))) = pci_read_config32(MCU, 0x78); + *((u32 *) (&(dly[4]))) = pci_read_config32(MCU, 0x7c); +} + +static void vx900_write_0x78_0x7f(const timing_dly dly) +{ + pci_write_config32(MCU, 0x78, *((u32 *) (&(dly[0])))); + pci_write_config32(MCU, 0x7c, *((u32 *) (&(dly[4])))); +} + +static void vx900_read_delay_range(delay_range * d_range, u8 mode) +{ + vx900_delay_calib_mode_select(mode, CALIB_LOWER); + vx900_read_0x78_0x7f(d_range->low); + vx900_delay_calib_mode_select(mode, CALIB_AVERAGE); + vx900_read_0x78_0x7f(d_range->avg); + vx900_delay_calib_mode_select(mode, CALIB_UPPER); + vx900_read_0x78_0x7f(d_range->high); +} + +static void dump_delay(const timing_dly dly) +{ + u8 i; + for (i = 0; i < 8; i++) { + printram(" %.2x", dly[i]); + } + printram("\n"); +} + +static void dump_delay_range(const delay_range d_range) +{ + printram("Lower limit: "); + dump_delay(d_range.low); + printram("Average: "); + dump_delay(d_range.avg); + printram("Upper limit: "); + dump_delay(d_range.high); +} + +/* + * These are some "safe" values that can be used for memory initialization. + * Some will stay untouched, and others will be overwritten later on + */ +static pci_reg8 mcu_init_config[] = { + {0x40, 0x01}, /* Virtual rank 0 ending address = 64M - 1 */ + {0x41, 0x00}, {0x42, 0x00}, {0x43, 0x00}, /* Virtual Ranks ending */ + {0x48, 0x00}, /* Virtual rank 0 starting address = 0 */ + {0x49, 0x00}, {0x4a, 0x00}, {0x4b, 0x00}, /* Virtual Ranks beginning */ + {0x50, 0xd8}, /* Set ranks 0-3 to 11 col bits, 16 row bits */ + /* Disable all virtual ranks */ + {0x54, 0x00}, {0x55, 0x00}, {0x56, 0x00}, {0x57, 0x00}, + /* Disable rank interleaving in ranks 0-3 */ + {0x58, 0x00}, {0x59, 0x00}, {0x5a, 0x00}, {0x5b, 0x00}, + {0x6c, 0xA0}, /* Memory type: DDR3, VDIMM: 1.5V, 64-bit DRAM */ + {0xc4, 0x80}, /* Enable 8 memory banks */ + {0xc6, 0x80}, /* Minimum latency from self-refresh. Bit [7] must be 1 */ + /* FIXME: do it here or in Final config? */ + {0xc8, 0x80}, /* Enable automatic triggering of short ZQ calibration */ + {0x99, 0xf0}, /* Power Management and Bypass Reorder Queue */ + /* Enable differential DQS; MODT assertion values suggested in DS */ + {0x9e, 0xa1}, {0x9f, 0x51}, + /* DQ/DQM Duty Control - Do not put any extra delays */ + {0xe9, 0x00}, {0xea, 0x00}, {0xeb, 0x00}, {0xec, 0x00}, + {0xed, 0x00}, {0xee, 0x00}, {0xef, 0x00}, + {0xfc, 0x00}, {0xfd, 0x00}, {0xfe, 0x00}, {0xff, 0x00}, + /* The following parameters we may or may not change */ + {0x61, 0x2e}, /* DRAMC Pipeline Control */ + {0x77, 0x10}, /* MDQS Output Control */ + + /* The following are parameters we'll most likely never change again */ + {0x60, 0xf4}, /* DRAM Pipeline Turn-Around Setting */ + {0x65, 0x49}, /* DRAM Arbitration Bandwidth Timer - I */ + {0x66, 0x80}, /* DRAM Queue / Arbitration */ + {0x69, 0xc6}, /* Bank Control: 8 banks, high priority refresh */ + {0x6a, 0xfc}, /* DRAMC Request Reorder Control */ + {0x6e, 0x38}, /* Burst lenght: 8, burst-chop: enable */ + {0x73, 0x04}, /* Close All Pages Threshold */ + + /* The following need to be dynamically asserted */ + /* See: check_special_registers.c */ + {0x74, 0xa0}, /* Yes, same 0x74; add one more T */ + {0x76, 0x60}, /* Write Data Phase Control */ + +}; + +/* + * This table keeps the driving strength control setting that we can safely use + * during initialization. This settings come in part from SerialICE, and in part + * from code provided by VIA. + */ +static pci_reg8 mcu_drv_ctrl_config[] = { + {0xd3, 0x03}, /* Enable auto-compensation circuit for ODT strength */ + {0xd4, 0x80}, /* Set internal ODT to dynamically turn on or off */ + {0xd6, 0x20}, /* Enable strong driving for MA and DRAM commands */ + {0xd0, 0x88}, /* (ODT) Strength ?has effect? */ + {0xe0, 0x88}, /* DRAM Driving – Group DQS (MDQS) */ + {0xe1, 0x00}, /* Disable offset mode for driving strength control */ + {0xe2, 0x88}, /* DRAM Driving – Group DQ (MD, MDQM) */ + {0xe4, 0xcc}, /* DRAM Driving – Group CSA (MCS, MCKE, MODT) */ + {0xe8, 0x88}, /* DRAM Driving – Group MA (MA, MBA, MSRAS, MSCAS, MSWE) */ + {0xe6, 0xff}, /* DRAM Driving – Group DCLK0 (DCLK[2:0] for DIMM0) */ + {0xe7, 0xff}, /* DRAM Driving – Group DCLK1 (DCLK[5:3] for DIMM1) */ + {0xe4, 0xcc}, /* DRAM Driving – Group CSA (MCS, MCKE, MODT) */ + {0x91, 0x08}, /* MCLKO Output Phase Delay - I */ + {0x92, 0x08}, /* MCLKO Output Phase Delay - II */ + {0x93, 0x16}, /* CS/CKE Output Phase Delay */ + {0x95, 0x16}, /* SCMD/MA Output Phase Delay */ + {0x9b, 0x3f}, /* Memory Clock Output Enable */ +}; + +static void vx900_dram_set_ma_pin_map(u16 map) +{ + pci_write_config16(MCU, 0x52, map); +} + +/* + * FIXME: This function is a complete waste of space. All we really need is a + * MA MAP table based on either row address bits or column address bits. + * The problem is, I do not know if this mapping is applied during the column + * access or during the row access. At least the religiously verbose output + * makes pretty console output. + */ +static void vx900_dram_map_pins(u8 ba0, u8 ba1, u8 ba2, u8 ra0, u8 ra1) +{ + u16 map = 0; + + printram("Mapping address pins to DRAM pins:\n"); + printram(" BA0 -> A%u\n", ba0); + printram(" BA1 -> A%u\n", ba1); + printram(" BA2 -> A%u\n", ba2); + printram(" RA0 -> A%u\n", ra0); + printram(" RA1 -> A%u\n", ra1); + /* Make sure BA2 is enabled */ + map |= (1 << 11); + + /* + * Find RA1 (15:14) + * 00: A14 + * 01: A16 + * 10: A18 + * 11: A20 + */ + if ((ra1 & 0x01) || (ra1 < 14) || (ra1 > 20)) { + printram("Illegal mapping RA1 -> A%u\n", ra1); + return; + } + map |= (((ra1 - 14) >> 1) & 0x03) << 14; + + /* + * Find RA0 (13:12) + * 00: A15 + * 01: A17 + * 10: A19 + * 11: A21 + */ + if ((!(ra0 & 0x01)) || (ra0 < 15) || (ra0 > 21)) { + printram("Illegal mapping RA0 -> A%u\n", ra0); + return; + } + map |= (((ra0 - 15) >> 1) & 0x03) << 12; + + /* + * Find BA2 (10:8) + * x00: A14 + * x01: A15 + * x10: A18 + * x11: A19 + */ + switch (ba2) { + case 14: + map |= (0 << 8); + break; + case 15: + map |= (1 << 8); + break; + case 18: + map |= (2 << 8); + break; + case 19: + map |= (3 << 8); + break; + default: + printram("Illegal mapping BA2 -> A%u\n", ba2); + break; + } + + /* + * Find BA1 (6:4) + * 000: A12 + * 001: A14 + * 010: A16 + * 011: A18 + * 1xx: A20 + */ + if (((ba1 & 0x01)) || (ba1 < 12) || (ba1 > 20)) { + printram("Illegal mapping BA1 -> A%u\n", ba1); + return; + } + map |= (((ba1 - 12) >> 1) & 0x07) << 4; + + /* + * Find BA0 (2:0) + * 000: A11 + * 001: A13 + * 010: A15 + * 011: A17 + * 1xx: A19 + */ + if ((!(ba0 & 0x01)) || (ba0 < 11) || (ba0 > 19)) { + printram("Illegal mapping BA0 -> A%u\n", ba0); + return; + } + map |= (((ba0 - 11) >> 1) & 0x07) << 0; + + printram("Setting map mask (rx52) to %.4x\n", map); + vx900_dram_set_ma_pin_map(map); +} + +static void vx900_dram_write_init_config(void) +{ + /* Keep our RAM space free of legacy stuff */ + vx900_disable_legacy_rom_shadow(); + + /* Now worry about the real RAM init */ + size_t i; + for (i = 0; i < (sizeof(mcu_init_config) / sizeof(pci_reg8)); i++) { + pci_write_config8(MCU, mcu_init_config[i].addr, + mcu_init_config[i].val); + } + vx900_dram_set_ma_pin_map(VX900_CALIB_MA_MAP); + + /* FIXME: Slowing stuff down. Does this really help? */ + + /* Fast cycle control for CPU-to-DRAM Read Cycle 0:Disabled. + * This CPU bus controller will wait for all data */ + ////pci_mod_config8(HOST_BUS, 0x51, (1 << 7), 0); + /* Memory to CPU bus Controller Conversion Mode 1: Synchronous mode */ + ////pci_mod_config8(HOST_BUS, 0x54, 0, (1 << 1)); +} + +static void dram_find_spds_ddr3(const dimm_layout * addr, dimm_info * dimm) +{ + size_t i = 0; + int dimms = 0; + do { + spd_raw_data spd; + spd_read(addr->spd_addr[i], spd); + spd_decode_ddr3(&dimm->dimm[i], spd); + if (dimm->dimm[i].dram_type != SPD_MEMORY_TYPE_SDRAM_DDR3) + continue; + dimms++; + dram_print_spd_ddr3(&dimm->dimm[i]); + } while (addr->spd_addr[++i] != SPD_END_LIST + && i < VX900_MAX_DIMM_SLOTS); + + if (!dimms) + die("No DIMMs were found"); +} + +static void dram_find_common_params(const dimm_info * dimms, + ramctr_timing * ctrl) +{ + size_t i, valid_dimms; + memset(ctrl, 0, sizeof(ramctr_timing)); + ctrl->cas_supported = 0xff; + valid_dimms = 0; + for (i = 0; i < VX900_MAX_DIMM_SLOTS; i++) { + const dimm_attr *dimm = &dimms->dimm[i]; + if (dimm->dram_type == SPD_MEMORY_TYPE_UNDEFINED) + continue; + valid_dimms++; + + if (valid_dimms == 1) { + /* First DIMM defines the type of DIMM */ + ctrl->dram_type = dimm->dram_type; + } else { + /* Check if we have mismatched DIMMs */ + if (ctrl->dram_type != dimm->dram_type) + die("Mismatched DIMM Types"); + } + /* Find all possible CAS combinations */ + ctrl->cas_supported &= dimm->cas_supported; + + /* Find the smallest common latencies supported by all DIMMs */ + ctrl->tCK = max(ctrl->tCK, dimm->tCK); + ctrl->tAA = max(ctrl->tAA, dimm->tAA); + ctrl->tWR = max(ctrl->tWR, dimm->tWR); + ctrl->tRCD = max(ctrl->tRCD, dimm->tRCD); + ctrl->tRRD = max(ctrl->tRRD, dimm->tRRD); + ctrl->tRP = max(ctrl->tRP, dimm->tRP); + ctrl->tRAS = max(ctrl->tRAS, dimm->tRAS); + ctrl->tRC = max(ctrl->tRC, dimm->tRC); + ctrl->tRFC = max(ctrl->tRFC, dimm->tRFC); + ctrl->tWTR = max(ctrl->tWTR, dimm->tWTR); + ctrl->tRTP = max(ctrl->tRTP, dimm->tRTP); + ctrl->tFAW = max(ctrl->tFAW, dimm->tFAW); + + } + + ctrl->n_dimms = valid_dimms; + if (!ctrl->cas_supported) + die("Unsupported DIMM combination. " + "DIMMS do not support common CAS latency"); + if (!valid_dimms) + die("No valid DIMMs found"); +} + +static void vx900_dram_phys_bank_range(const dimm_info * dimms, + rank_layout * ranks) +{ + size_t i; + for (i = 0; i < VX900_MAX_DIMM_SLOTS; i++) { + if (dimms->dimm[i].dram_type == SPD_MEMORY_TYPE_UNDEFINED) + continue; + u8 nranks = dimms->dimm[i].ranks; + /* Make sure we save the flags */ + ranks->flags[i * 2 + 1] = ranks->flags[i * 2] = + dimms->dimm[i].flags; + /* Only Rank1 has a mirrored pin mapping */ + ranks->flags[i * 2].pins_mirrored = 0; + if (nranks > 2) + die("Found DIMM with more than two ranks, which is not " + "supported by this chipset"); + u32 size = dimms->dimm[i].size_mb; + if (nranks == 2) { + /* Each rank holds half the capacity of the DIMM */ + size >>= 1; + ranks->phys_rank_size_mb[i << 1] = size; + ranks->phys_rank_size_mb[(i << 1) | 1] = size; + } else { + /* Otherwise, everything is held in the first bank */ + ranks->phys_rank_size_mb[i << 1] = size; + ranks->phys_rank_size_mb[(i << 1) | 1] = 0;; + } + } +} + +#define ODT_R0 0 +#define ODT_R1 1 +#define ODT_R2 2 +#define ODT_R3 3 +/* + * This is the table that tells us which MODT pin to map to which rank. + * + * This table is taken from code provided by VIA, but no explanation was + * provided as to why it is done this way. It may be possible that this table is + * not suitable for the way we map ranks later on. + */ +static const u8 odt_lookup_table[][2] = { + /* RankMAP Rank 3 Rank 2 Rank 1 Rank 0 */ + {0x01, (ODT_R3 << 6) | (ODT_R2 << 4) | (ODT_R1 << 2) | (ODT_R0 << 0)}, + {0x03, (ODT_R3 << 6) | (ODT_R2 << 4) | (ODT_R0 << 2) | (ODT_R1 << 0)}, + {0x04, (ODT_R3 << 6) | (ODT_R2 << 4) | (ODT_R1 << 2) | (ODT_R0 << 0)}, + {0x05, (ODT_R3 << 6) | (ODT_R0 << 4) | (ODT_R1 << 2) | (ODT_R2 << 0)}, + {0x07, (ODT_R3 << 6) | (ODT_R0 << 4) | (ODT_R2 << 2) | (ODT_R2 << 0)}, + {0x0c, (ODT_R2 << 6) | (ODT_R3 << 4) | (ODT_R1 << 2) | (ODT_R0 << 0)}, + {0x0d, (ODT_R0 << 6) | (ODT_R0 << 4) | (ODT_R1 << 2) | (ODT_R2 << 0)}, + {0x0f, (ODT_R0 << 6) | (ODT_R0 << 4) | (ODT_R2 << 2) | (ODT_R2 << 0)}, + {0, 0}, +}; + +static void vx900_dram_driving_ctrl(const dimm_info * dimm) +{ + size_t i, ndimms; + u8 reg8, regxd5, rank_mask; + + rank_mask = 0; + /* For ODT range selection, datasheet recommends + * when 1 DIMM present: 60 Ohm + * when 2 DIMMs present: 120 Ohm */ + ndimms = 0; + for (i = 0; i < VX900_MAX_DIMM_SLOTS; i++) { + if (dimm->dimm[i].dram_type != SPD_MEMORY_TYPE_SDRAM_DDR3) + continue; + ndimms++; + rank_mask |= (1 << (i * 2)); + if (dimm->dimm[i].ranks > 1) + rank_mask |= (2 << (i * 2)); + } + /* ODT strength and MD/MDQM/MDQS driving strength */ + if (ndimms > 1) { + /* Enable 1 ODT block (120 Ohm ODT) */ + regxd5 = 0 << 2; + /* Enable strong driving for MD/MDQM/MDQS */ + regxd5 |= (1 << 7); + } else { + /* Enable 2 ODT blocks (60 Ohm ODT) */ + regxd5 = 1 << 2; + /* Leave MD/MDQM/MDQS driving weak */ + } + pci_write_config8(MCU, 0xd5, regxd5); + + /* Enable strong CLK driving for DIMMs with more than one rank */ + if (dimm->dimm[0].ranks > 1) + pci_mod_config8(MCU, 0xd6, 0, (1 << 7)); + if (dimm->dimm[1].ranks > 1) + pci_mod_config8(MCU, 0xd6, 0, (1 << 6)); + + /* DRAM ODT Lookup Table */ + for (i = 0;; i++) { + if (odt_lookup_table[i][0] == 0) { + printram("No ODT entry for rank mask %x\n", rank_mask); + die("Aborting"); + } + if (odt_lookup_table[i][0] != rank_mask) + continue; + + reg8 = odt_lookup_table[i][1]; + break; + } + + printram("Mapping rank mask %x to ODT entry %.2x\n", rank_mask, reg8); + pci_write_config8(MCU, 0x9c, reg8); + + for (i = 0; i < (sizeof(mcu_drv_ctrl_config) / sizeof(pci_reg8)); i++) { + pci_write_config8(MCU, mcu_drv_ctrl_config[i].addr, + mcu_drv_ctrl_config[i].val); + } +} + +static void vx900_pr_map_all_vr3(void) +{ + /* Enable all ranks and set them to VR3 */ + pci_write_config16(MCU, 0x54, 0xbbbb); +} + +/* Map physical rank pr to virtual rank vr */ +static void vx900_map_pr_vr(u8 pr, u8 vr) +{ + u16 val; + + pr &= 0x3; + vr &= 0x3; + /* Enable rank (bit [3], and set the VR number bits [1:0] */ + val = 0x8 | vr; + /* Now move the value to the appropriate PR */ + val <<= (pr * 4); + pci_mod_config16(MCU, 0x54, 0xf << (pr * 4), val); + printram("Mapping PR %u to VR %u\n", pr, vr); +} + +static u8 vx900_get_CWL(u8 CAS) +{ + /* Get CWL based on CAS using the following rule: + * _________________________________________ + * CAS: | 4T | 5T | 6T | 7T | 8T | 9T | 10T | 11T | + * CWL: | 5T | 5T | 5T | 6T | 6T | 7T | 7T | 8T | + */ + static const u8 cas_cwl_map[] = { 5, 5, 5, 6, 6, 7, 7, 8 }; + if (CAS > 11) + return 8; + return cas_cwl_map[CAS - 4]; +} + +/* + * Here we are calculating latencies, and writing them to the appropriate + * registers. Note that some registers do not take latencies from 0 = 0T, + * 1 = 1T, so each register gets its own math formula. + */ +static void vx900_dram_timing(ramctr_timing * ctrl) +{ + u8 reg8, val, tFAW, tRRD; + u32 val32; + + /* Maximum supported DDR3 frequency is 533MHz (DDR3 1066) so make sure + * we cap it if we have faster DIMMs. + * Then, align it to the closest JEDEC standard frequency */ + if (ctrl->tCK <= TCK_533MHZ) { + ctrl->tCK = TCK_533MHZ; + } else if (ctrl->tCK <= TCK_400MHZ) { + ctrl->tCK = TCK_400MHZ; + } else if (ctrl->tCK <= TCK_333MHZ) { + ctrl->tCK = TCK_333MHZ; + } else { + ctrl->tCK = TCK_266MHZ; + } + + val32 = (1000 << 8) / ctrl->tCK; + printram("Selected DRAM frequency: %u MHz\n", val32); + + /* Find CAS and CWL latencies */ + val = (ctrl->tAA + ctrl->tCK - 1) / ctrl->tCK; + printram("Minimum CAS latency : %uT\n", val); + /* Find lowest supported CAS latency that satisfies the minimum value */ + while (!((ctrl->cas_supported >> (val - 4)) & 1) + && (ctrl->cas_supported >> (val - 4))) { + val++; + } + /* Is CAS supported */ + if (!(ctrl->cas_supported & (1 << (val - 4)))) + printram("CAS not supported\n"); + printram("Selected CAS latency : %uT\n", val); + ctrl->CAS = val; + ctrl->CWL = vx900_get_CWL(ctrl->CAS); + printram("Selected CWL latency : %uT\n", ctrl->CWL); + /* Write CAS and CWL */ + reg8 = (((ctrl->CWL - 4) & 0x07) << 4) | ((ctrl->CAS - 4) & 0x07); + pci_write_config8(MCU, 0xc0, reg8); + + /* Find tRCD */ + val = (ctrl->tRCD + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tRCD : %uT\n", val); + reg8 = ((val - 4) & 0x7) << 4; + /* Find tRP */ + val = (ctrl->tRP + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tRP : %uT\n", val); + reg8 |= ((val - 4) & 0x7); + pci_write_config8(MCU, 0xc1, reg8); + + /* Find tRAS */ + val = (ctrl->tRAS + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tRAS : %uT\n", val); + reg8 = ((val - 15) & 0x7) << 4; + /* Find tWR */ + ctrl->WR = (ctrl->tWR + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tWR : %uT\n", ctrl->WR); + reg8 |= ((ctrl->WR - 4) & 0x7); + pci_write_config8(MCU, 0xc2, reg8); + + /* Find tFAW */ + tFAW = (ctrl->tFAW + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tFAW : %uT\n", tFAW); + /* Find tRRD */ + tRRD = (ctrl->tRRD + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tRRD : %uT\n", tRRD); + val = tFAW - 4 * tRRD; /* number of cycles above 4*tRRD */ + reg8 = ((val - 0) & 0x7) << 4; + reg8 |= ((tRRD - 2) & 0x7); + pci_write_config8(MCU, 0xc3, reg8); + + /* Find tRTP */ + val = (ctrl->tRTP + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tRTP : %uT\n", val); + reg8 = ((val & 0x3) << 4); + /* Find tWTR */ + val = (ctrl->tWTR + ctrl->tCK - 1) / ctrl->tCK; + printram("Selected tWTR : %uT\n", val); + reg8 |= ((val - 2) & 0x7); + pci_mod_config8(MCU, 0xc4, 0x3f, reg8); + + /* DRAM Timing for All Ranks - VI + * [7:6] CKE Assertion Minimum Pulse Width + * We probably don't want to mess with this just yet. + * [5:0] Refresh-to-Active or Refresh-to-Refresh (tRFC) + * tRFC = (30 + 2 * [5:0])T + * Since we previously set RxC4[7] + */ + reg8 = pci_read_config8(MCU, 0xc5); + val = (ctrl->tRFC + ctrl->tCK - 1) / ctrl->tCK; + printram("Minimum tRFC : %uT\n", val); + if (val < 30) { + val = 0; + } else { + val = (val - 30 + 1) / 2; + } + ; + printram("Selected tRFC : %uT\n", 30 + 2 * val); + reg8 |= (val & 0x3f); + pci_write_config8(MCU, 0xc5, reg8); + + /* Where does this go??? */ + val = (ctrl->tRC + ctrl->tCK - 1) / ctrl->tCK; + printram("Required tRC : %uT\n", val); +} + +/* Program the DRAM frequency */ +static void vx900_dram_freq(ramctr_timing * ctrl) +{ + u8 val; + + /* Step 1 - Reset the PLL */ + pci_mod_config8(MCU, 0x90, 0x00, 0x0f); + /* Wait at least 10 ns; VIA code delays by 640us */ + udelay(640); + + /* Step 2 - Set target frequency */ + if (ctrl->tCK <= TCK_533MHZ) { + val = 0x07; + ctrl->tCK = TCK_533MHZ; + } else if (ctrl->tCK <= TCK_400MHZ) { + val = 0x06; + ctrl->tCK = TCK_400MHZ; + } else if (ctrl->tCK <= TCK_333MHZ) { + val = 0x05; + ctrl->tCK = TCK_333MHZ; + } else { /*ctrl->tCK <= TCK_266MHZ */ + val = 0x04; + ctrl->tCK = TCK_266MHZ; + } + /* Restart the PLL with the desired frequency */ + pci_mod_config8(MCU, 0x90, 0x0f, val); + + /* Step 3 - Wait for PLL to stabilize */ + udelay(2000); + + /* Step 4 - Reset the DLL - Clear [7,4] */ + pci_mod_config8(MCU, 0x6b, 0x90, 0x00); + udelay(2000); + + /* Step 5 - Enable the DLL - Set bits [7,4] to 01b */ + pci_mod_config8(MCU, 0x6b, 0x00, 0x10); + udelay(2000); + + /* Step 6 - Start DLL Calibration - Set bit [7] */ + pci_mod_config8(MCU, 0x6b, 0x00, 0x80); + udelay(5); + + /* Step 7 - Finish DLL Calibration - Clear bit [7] */ + pci_mod_config8(MCU, 0x6b, 0x80, 0x00); + + /* Step 8 - If we have registered DIMMs, we need to set bit[0] */ + if (dimm_is_registered(ctrl->dram_type)) { + printram("Enabling RDIMM support in memory controller\n"); + pci_mod_config8(MCU, 0x6c, 0x00, 0x01); + } +} + +/* + * The VX900 can send the MRS commands directly through hardware + * It does the MR2->MR3->MR1->MR0->LongZQ JEDEC dance + * The parameters that we don't worry about are extracted from the timing + * registers we have programmed earlier. + */ +static void vx900_dram_ddr3_do_hw_mrs(u8 ma_swap, u8 rtt_nom, + u8 ods, u8 rtt_wr, u8 srt, u8 asr) +{ + u16 reg16 = 0; + + printram("Using Hardware method for DRAM MRS commands.\n"); + + reg16 |= ((rtt_wr & 0x03) << 12); + if (srt) + reg16 |= (1 << 9); + if (asr) + reg16 |= (1 << 8); + reg16 |= ((rtt_nom & 0x7) << 4); + reg16 |= ((ods & 0x03) << 2); + if (ma_swap) + reg16 |= (1 << 1); + reg16 |= (1 << 14); + reg16 |= (1 << 0); /* This is the trigger bit */ + printram("Hw MRS set is 0x%4x\n", reg16); + pci_write_config16(MCU, 0xcc, reg16); + /* Wait for MRS commands to be sent */ + while (pci_read_config8(MCU, 0xcc) & 1) ; +} + +/* + * Translate the MRS command into an address on the CPU bus + * + * Take an MRS command (mrs_cmd_t) and translate it to a read address on the CPU + * bus. Thus, reading from the returned address, will issue the correct MRS + * command, assuming we are in MRS mode, of course. + * + * A read from the returned address will produce the correct MRS command + * provided the following conditions are met: + * - The MA pin mapping is set to VX900_MRS_MA_MAP + * - The memory controller's Fun3_RX6B[2:0] is set to 011b (MSR Enable) + */ +static u32 vx900_get_mrs_addr(mrs_cmd_t cmd) +{ + u32 addr = 0; + u8 mrs_type = (cmd >> 16) & 0x07; + /* MA[9:0] <-> A[12:3] */ + addr |= ((cmd & 0x3ff) << 3); + /* MA10 <-> A20 */ + addr |= (((cmd >> 10) & 0x1) << 20); + /* MA[12:11] <-> A[14:13] */ + addr |= (((cmd >> 11) & 0x3) << 13); + /* BA[2:0] <-> A[19:17] */ + addr |= mrs_type << 17; + return addr; +} + +/* + * Here, we do the MR2->MR3->MR1->MR0->LongZQ JEDEC dance manually + * + * Why would we do this in software, when the VX900 can do it in hardware? The + * problem is the hardware sequence seems to be buggy on ranks with mirrored + * pins. Is this a hardware bug or a misconfigured MCU? No idea. + * + * To maintain API compatibility with the function that implements the hardware + * sequence, we don't ask for all parameters. To keep an overall cleaner code + * structure, we don't try to pass down all that information. Instead, we + * extract the extra parameters from the timing registers we have programmed + * earlier. + */ +static void vx900_dram_ddr3_do_sw_mrs(u8 ma_swap, enum ddr3_mr1_rtt_nom rtt_nom, + enum ddr3_mr1_ods ods, + enum ddr3_mr2_rttwr rtt_wr, + enum ddr3_mr2_srt_range srt, + enum ddr3_mr2_asr asr) +{ + mrs_cmd_t mrs; + u8 reg8, cas, cwl, twr; + + printram("Using Software method for DRAM MRS commands.\n"); + + /* Get CAS, CWL, and tWR that we programmed earlier */ + reg8 = pci_read_config8(MCU, 0xc0); + cas = (reg8 & 0x07) + 4; + cwl = ((reg8 >> 4) & 0x07) + 4; + reg8 = pci_read_config8(MCU, 0xc2); + twr = (reg8 & 0x07) + 4; + + /* Step 06 - Set Fun3_RX6B[2:0] to 001b (NOP Command Enable). */ + /* Was already done for us before calling us */ + + /* Step 07 - Read a double word from any address of the DIMM. */ + /* Was already done for us before calling us */ + + /* Step 08 - Set Fun3_RX6B[2:0] to 011b (MSR Enable). */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x03); /* MSR Enable */ + + /* Step 09 – Issue MR2 cycle. Read a double word from the address + * depended on DRAM’s Rtt_WR and CWL settings. */ + mrs = ddr3_get_mr2(rtt_wr, srt, asr, cwl); + if (ma_swap) + mrs = ddr3_mrs_mirror_pins(mrs); + volatile_read(vx900_get_mrs_addr(mrs)); + printram("MR2: %.5x\n", mrs); + udelay(1000); + + /* Step 10 – Issue MR3 cycle. Read a double word from the address 60000h + * to set DRAM to normal operation mode. */ + mrs = ddr3_get_mr3(0); + if (ma_swap) + mrs = ddr3_mrs_mirror_pins(mrs); + volatile_read(vx900_get_mrs_addr(mrs)); + printram("MR3: %.5x\n", mrs); + udelay(1000); + + /* Step 11 –Issue MR1 cycle. Read a double word from the address + * depended on DRAM’s output driver impedance and Rtt_Nom settings. + * The DLL enable field, TDQS field, write leveling enable field, + * additive latency field and Qoff field should be set to 0. */ + mrs = ddr3_get_mr1(DDR3_MR1_QOFF_ENABLE, DDR3_MR1_TQDS_DISABLE, rtt_nom, + DDR3_MR1_WRLVL_DISABLE, ods, DDR3_MR1_AL_DISABLE, + DDR3_MR1_DLL_ENABLE); + if (ma_swap) + mrs = ddr3_mrs_mirror_pins(mrs); + volatile_read(vx900_get_mrs_addr(mrs)); + printram("MR1: %.5x\n", mrs); + udelay(1000); + + /* Step 12 - Issue MR0 cycle. Read a double word from the address + * depended on DRAM’s burst length, CAS latency and write recovery time + * settings. + * The read burst type field should be set to interleave. + * The mode field should be set to normal mode. + * The DLL reset field should be set to No. + * The DLL control for precharge PD field should be set to Fast exit. + */ + mrs = ddr3_get_mr0(DDR3_MR0_PRECHARGE_FAST, twr, + DDR3_MR0_DLL_RESET_NO, DDR3_MR0_MODE_NORMAL, cas, + DDR3_MR0_BURST_TYPE_INTERLEAVED, + DDR3_MR0_BURST_LENGTH_CHOP); + volatile_read(vx900_get_mrs_addr(mrs)); + printram("MR0: %.5x\n", mrs); + udelay(1000); + + /* Step 13 - Set Fun3_RX6B[2:0] to 110b (Long ZQ calibration cmd) */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x06); /* Long ZQ */ + /* Step 14 - Read a double word from any address of the DIMM. */ + volatile_read(0); + udelay(1000); +} + +/* + * This is where we take the DIMMs out of reset and do the JEDEC dance for each + * individual physical rank. + */ +static void vx900_dram_ddr3_dimm_init(const ramctr_timing * ctrl, + const rank_layout * ranks) +{ + size_t i; + u8 rtt_nom, rtt_wr, ods, pinswap; + + /* Set BA[0/1/2] to [A17/18/19] */ + vx900_dram_set_ma_pin_map(VX900_MRS_MA_MAP); + + /* Step 01 - Set Fun3_Rx6E[5] to 1b to support burst length. */ + pci_mod_config8(MCU, 0x6e, 0, 1 << 5); + /* Step 02 - Set Fun3_RX69[0] to 0b (Disable Multiple Page Mode). */ + pci_mod_config8(MCU, 0x69, (1 << 0), 0x00); + /* And set [7:6] to 10b ? */ + pci_write_config8(MCU, 0x69, 0x87); + + /* Step 03 - Set the target physical rank to virtual rank0 and other + * ranks to virtual rank3. */ + vx900_pr_map_all_vr3(); + + /* Step 04 - Set Fun3_Rx50 to D8h. */ + pci_write_config8(MCU, 0x50, 0xd8); + /* Step 05 - Set Fun3_RX6B[5] to 1b to de-assert RESET# and wait for at + * least 500 us. */ + pci_mod_config8(MCU, 0x6b, 0x00, (1 << 5)); + udelay(500); + + /* Step 6 -> 15 - Set the target physical rank to virtual rank 0 and + * other ranks to virtual rank 3. + * Repeat Step 6 to 14 for every rank present, then jump to Step 16. */ + for (i = 0; i < VX900_MAX_MEM_RANKS; i++) { + if (ranks->phys_rank_size_mb[i] == 0) + continue; + printram("Initializing rank %lu\n", i); + + /* Set target physical rank to virtual rank 0 + * other ranks to virtual rank 3*/ + vx900_map_pr_vr(i, 0); + + /* FIXME: Is this needed on HW init? */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x01); /* Enable NOP */ + volatile_read(0x0); /* Do NOP */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x03); /* MSR Enable */ + + /* See init_dram_by_rank.c and get_basic_information.c + * in the VIA provided code */ + if (ctrl->n_dimms == 1) { + rtt_nom = DDR3_MR1_RTT_NOM_RZQ2; + rtt_wr = DDR3_MR2_RTTWR_OFF; + } else { + rtt_nom = DDR3_MR1_RTT_NOM_RZQ8; + rtt_wr = DDR3_MR2_RTTWR_RZQ2; + } + ods = ranks->flags[i].rzq7_supported ? + DDR3_MR1_ODS_RZQ7 : DDR3_MR1_ODS_RZQ6; + + pinswap = (ranks->flags[i].pins_mirrored); + if (pinswap) + printram("Pins mirrored\n"); + printram(" Swap : %x\n", pinswap); + printram(" rtt_nom : %x\n", rtt_nom); + printram(" ods : %x\n", ods); + printram(" rtt_wr : %x\n", rtt_wr); + if (RAMINIT_USE_HW_MRS_SEQ) + vx900_dram_ddr3_do_hw_mrs(pinswap, rtt_nom, ods, rtt_wr, + 0, 0); + else + vx900_dram_ddr3_do_sw_mrs(pinswap, rtt_nom, ods, rtt_wr, + 0, 0); + + /* Normal SDRAM Mode */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x00); + + /* Step 15, set the rank to virtual rank 3 */ + vx900_map_pr_vr(i, 3); + } + + /* Step 16 – Set Fun3_Rx6B[2:0] to 000b (Normal SDRAM Mode). */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x00); + + /* Set BA[0/1/2] to [A13/14/15] */ + vx900_dram_set_ma_pin_map(VX900_CALIB_MA_MAP); + + /* Step 17 – Set Fun3_Rx69[0] to 1b (Enable Multiple Page Mode). */ + pci_mod_config8(MCU, 0x69, 0x00, (1 << 0)); + + printram("DIMM initialization sequence complete\n"); +} + +/* + * This a small utility to send a single MRS command, but where we don't want to + * have to worry about changing the MCU mode. It gives the MCU back to us in + * normal operating mode. + */ +static void vx900_dram_send_soft_mrs(mrs_cmd_t cmd, u8 pin_swap) +{ + u32 addr; + /* Set Fun3_RX6B[2:0] to 011b (MSR Enable). */ + pci_mod_config8(MCU, 0x6b, 0x07, (3 << 0)); + /* Is this a funky rank with Address pins swapped? */ + if (pin_swap) + cmd = ddr3_mrs_mirror_pins(cmd); + /* Find the address corresponding to the MRS */ + addr = vx900_get_mrs_addr(cmd); + /* Execute the MRS */ + volatile_read(addr); + /* Set Fun3_Rx6B[2:0] to 000b (Normal SDRAM Mode). */ + pci_mod_config8(MCU, 0x6b, 0x07, 0x00); +} + +static void vx900_dram_enter_read_leveling(u8 pinswap) +{ + /* Precharge all before issuing read leveling MRS to DRAM */ + pci_mod_config8(MCU, 0x06b, 0x07, 0x02); + volatile_read(0x0); + udelay(1000); + + /* Enable read leveling: Set D0F3Rx71[7]=1 */ + pci_mod_config8(MCU, 0x71, 0, (1 << 7)); + + /* Put DRAM in read leveling mode */ + mrs_cmd_t cmd = ddr3_get_mr3(1); + vx900_dram_send_soft_mrs(cmd, pinswap); +} + +static void vx900_dram_exit_read_leveling(u8 pinswap) +{ + /* Disable read leveling, and put dram in normal operation mode */ + mrs_cmd_t cmd = ddr3_get_mr3(0); + vx900_dram_send_soft_mrs(cmd, pinswap); + + /* Disable read leveling: Set D0F3Rx71[7]=0 */ + pci_mod_config8(MCU, 0x71, (1 << 7), 0); +} + +/* + * We need to see if the delay window (difference between minimum and maximum) + * is large enough so that we actually have a valid window. The signal should be + * valid for at least 1/2T in general. If the window is significantly smaller, + * then chances are our window does not latch at the correct time, and the + * calibration will not work. + */ +#define DQSI_THRESHOLD 0x10 +#define DQO_THRESHOLD 0x09 +#define DQSO_THRESHOLD 0x12 +#define DELAY_RANGE_GOOD 0 +#define DELAY_RANGE_BAD -1 +static u8 vx900_dram_check_calib_range(const delay_range * dly, u8 window) +{ + size_t i; + for (i = 0; i < 8; i++) { + if (dly->high[i] - dly->low[i] < window) + return DELAY_RANGE_BAD; + /* When our maximum value is lower than our min, both values + * have overshot, and the window is definitely invalid */ + if (dly->high[i] < dly->low[i]) + return DELAY_RANGE_BAD; + } + return DELAY_RANGE_GOOD; +} + +static void vx900_dram_find_avg_delays(vx900_delay_calib * delays) +{ + size_t i; + u16 dq_low, dq_high, dqs_low, dqs_high, dq_final, dqs_final; + /* + * At this point, we have transmit delays for both DIMMA and DIMMB, each + * with a slightly different window We want to find the intersection of + * those windows, so that we have a constrained window which both + * DIMMA and DIMMB can use. The center of our constrained window will + * also be the safest setting for the transmit delays + * + * DIMMA window t:|xxxxxxxxxxxxxx---------------xxxxxxxxxxxxxxxxxxxxxxx| + * DIMMB window t:|xxxxxxxxxxxxxxxxxxx---------------xxxxxxxxxxxxxxxxxx| + * Safe window t:|xxxxxxxxxxxxxxxxxxx----------xxxxxxxxxxxxxxxxxxxxxxx| + */ + delay_range *tx_dq_a = &(delays->tx_dq[0]); + delay_range *tx_dq_b = &(delays->tx_dq[1]); + delay_range *tx_dqs_a = &(delays->tx_dqs[0]); + delay_range *tx_dqs_b = &(delays->tx_dqs[1]); + + for (i = 0; i < 8; i++) { + dq_low = max(tx_dq_a->low[i], tx_dq_b->low[i]); + dq_high = min(tx_dq_a->high[i], tx_dq_b->high[i]); + dqs_low = max(tx_dqs_a->low[i], tx_dqs_b->low[i]); + dqs_high = min(tx_dqs_a->high[i], tx_dqs_b->high[i]); + + /* Find the average */ + dq_final = ((dq_low + dq_high) / 2); + dqs_final = ((dqs_low + dqs_high) / 2); + + /* + * These adjustments are done in code provided by VIA. + * There is no explanation as to why this is done. + * + * We can get away without doing the DQS adjustment, but doing + * it, brings the values closer to what the vendor BIOS + * calibrates to. + */ + if ((dqs_final & 0x1f) >= 0x1c) + dqs_final -= 0x1c; + else + dqs_final += 0x04; + /* + * The DQ adjustment is more critical. If we don't do this + * adjustment our MCU won't be configured properly, and + * ram_check() will fail. + */ + if ((dq_final & 0x1f) >= 0x14) + dq_final -= 0x14; + else + dq_final += 0x0c; + + /* Store our values in the first delay */ + delays->tx_dq[0].avg[i] = dq_final; + delays->tx_dqs[0].avg[i] = dqs_final; + + } +} + +/* + * First calibration: When to receive data from the DRAM + * (MD and MDQS input delay) + * + * This calibration unfortunately does not seem to work. Whether this is due to + * a misconfigured MCU or hardware bug is unknown. + */ +static void vx900_rx_capture_range_calib(u8 pinswap) +{ + u8 reg8; + const u32 cal_addr = 0x20; + + /* Set IO calibration address */ + pci_mod_config16(MCU, 0x8c, 0xfff0, cal_addr & (0xfff0)); + /* Data pattern must be 0x00 for this calibration + * See paragraph describing Rx8e */ + pci_write_config8(MCU, 0x8e, 0x00); + + /* Need to put DRAM and MCU in read leveling */ + vx900_dram_enter_read_leveling(pinswap); + + /* Data pattern must be 0x00 for this calibration + * See paragraph describing Rx8e */ + pci_write_config8(MCU, 0x8e, 0x00); + /* Trigger calibration */ + reg8 = 0xa0; + pci_write_config8(MCU, 0x71, reg8); + + /* Wait for it */ + while (pci_read_config8(MCU, 0x71) & 0x10) ; + vx900_dram_exit_read_leveling(pinswap); +} + +/* + * Second calibration: How much to delay DQS signal by + * (MDQS input delay) + */ +static void vx900_rx_dqs_delay_calib(u8 pinswap) +{ + const u32 cal_addr = 0x30; + + /* We need to disable refresh commands so that they don't interfere */ + const u8 ref_cnt = pci_read_config8(MCU, 0xc7); + pci_write_config8(MCU, 0xc7, 0); + /* Set IO calibration address */ + pci_mod_config16(MCU, 0x8c, 0xfff0, cal_addr & (0xfff0)); + /* Data pattern must be 0x00 for this calibration + * See paragraph describing Rx8e */ + pci_write_config8(MCU, 0x8e, 0x00); + + /* Need to put DRAM and MCU in read leveling */ + vx900_dram_enter_read_leveling(pinswap); + + /* From VIA code; Undocumented + * In theory this enables MODT[3:0] to be asserted */ + pci_mod_config8(MCU, 0x9e, 0, 0x80); + + /* Trigger calibration: Set D0F3Rx71[1:0]=10b */ + pci_mod_config8(MCU, 0x71, 0x03, 0x02); + + /* Wait for calibration to complete */ + while (pci_read_config8(MCU, 0x71) & 0x02) ; + vx900_dram_exit_read_leveling(pinswap); + + /* Restore the refresh counter */ + pci_write_config8(MCU, 0xc7, ref_cnt); + + /* FIXME: should we save it before, or should we just set it as is */ + vx900_dram_set_ma_pin_map(VX900_CALIB_MA_MAP); +} + +static void vx900_tx_dqs_trigger_calib(u8 pattern) +{ + /* Data pattern for calibration */ + pci_write_config8(MCU, 0x8e, pattern); + /* Trigger calibration */ + pci_mod_config8(MCU, 0x75, 0, 0x20); + /* Wait for calibration */ + while (pci_read_config8(MCU, 0x75) & 0x20) ; +} + +/* + * Third calibration: How much to wait before asserting DQS + */ +static void vx900_tx_dqs_delay_calib(void) +{ + const u32 cal_addr = 0x00; + /* Set IO calibration address */ + pci_mod_config16(MCU, 0x8c, 0xfff0, cal_addr & (0xfff0)); + /* Set circuit to use calibration results - Clear Rx75[0] */ + pci_mod_config8(MCU, 0x75, 0x01, 0); + /* Run calibration with first data pattern */ + vx900_tx_dqs_trigger_calib(0x5a); + /* Run again with different pattern */ + vx900_tx_dqs_trigger_calib(0xa5); +} + +/* + * Fourt calibration: How much to wait before putting data on DQ lines + */ +static void vx900_tx_dq_delay_calib(void) +{ + /* Data pattern for calibration */ + pci_write_config8(MCU, 0x8e, 0x5a); + /* Trigger calibration */ + pci_mod_config8(MCU, 0x75, 0, 0x02); + /* Wait for calibration */ + while (pci_read_config8(MCU, 0x75) & 0x02) ; +} + +static void vx900_rxdqs_adjust(delay_range * dly) +{ + /* Adjust Rx DQS delay after calibration has been run. This is + * recommended by VIA, but no explanation was provided as to why */ + size_t i; + for (i = 0; i < 8; i++) { + if (dly->low[i] < 3) { + if (i == 2 || i == 4) + dly->avg[i] += 4; + else + dly->avg[i] += 3; + + } + + if (dly->high[i] > 0x38) + dly->avg[i] -= 6; + else if (dly->high[i] > 0x30) + dly->avg[i] -= 4; + + if (dly->avg[i] > 0x20) + dly->avg[i] = 0x20; + } + + /* Put Rx DQS delay into manual mode (Set Rx[2,0] to 01) */ + pci_mod_config8(MCU, 0x71, 0x05, 0x01); + /* Now write the new settings */ + vx900_delay_calib_mode_select(CALIB_RxDQS, CALIB_MANUAL); + vx900_write_0x78_0x7f(dly->avg); +} + +static void vx900_dram_calibrate_recieve_delays(vx900_delay_calib * delays, + u8 pinswap) +{ + size_t n_tries = 0; + delay_range *rx_dq_cr = &(delays->rx_dq_cr); + delay_range *rx_dqs = &(delays->rx_dqs); + /* We really should be able to finish this in a single pass, but it may + * in very rare circumstances not work the first time. We define a limit + * on the number of tries so that we have a way of warning the user */ + const size_t max_tries = 100; + for (;;) { + if (n_tries++ >= max_tries) { + die("Could not calibrate receive delays. Giving up"); + } + u8 result; + /* Run calibrations */ + if (RAMINIT_USE_HW_RXCR_CALIB) { + vx900_rx_capture_range_calib(pinswap); + vx900_read_delay_range(rx_dq_cr, CALIB_RxDQ_CR); + dump_delay_range(*rx_dq_cr); + + } else { + /*FIXME: Cheating with Rx CR setting\ + * We need to either use Rx CR calibration + * or set up a table for the calibration */ + u8 *override = &(rx_dq_cr->avg[0]); + override[0] = 0x28; + override[1] = 0x1c; + override[2] = 0x28; + override[3] = 0x28; + override[4] = 0x2c; + override[5] = 0x30; + override[6] = 0x30; + override[7] = 0x34; + printram("Bypassing RxCR 78-7f calibration with:\n"); + dump_delay(rx_dq_cr->avg); + } + /* We need to put the setting on manual mode */ + pci_mod_config8(MCU, 0x71, 0, 1 << 4); + vx900_delay_calib_mode_select(CALIB_RxDQ_CR, CALIB_MANUAL); + vx900_write_0x78_0x7f(rx_dq_cr->avg); + + /************* RxDQS *************/ + vx900_rx_dqs_delay_calib(pinswap); + vx900_read_delay_range(rx_dqs, CALIB_RxDQS); + vx900_rxdqs_adjust(rx_dqs); + + result = vx900_dram_check_calib_range(rx_dqs, DQSI_THRESHOLD); + if (result != DELAY_RANGE_GOOD) + continue; + + /* We're good to go. Switch to manual and write the manual + * setting */ + pci_mod_config8(MCU, 0x71, 0, 1 << 0); + vx900_delay_calib_mode_select(CALIB_RxDQS, CALIB_MANUAL); + vx900_write_0x78_0x7f(rx_dqs->avg); + break; + } + if (n_tries > 1) + printram("Hmm, we had to try %lu times before our calibration " + "was good.\n", n_tries); +} + +static void vx900_dram_calibrate_transmit_delays(delay_range * tx_dq, + delay_range * tx_dqs) +{ + /* Same timeout reasoning as in receive delays */ + size_t n_tries = 0; + int dq_tries = 0, dqs_tries = 0;; + const size_t max_tries = 100; + for (;;) { + if (n_tries++ >= max_tries) { + printram("Tried DQS %i times and DQ %i times\n", + dqs_tries, dq_tries); + printram("Tx DQS calibration results\n"); + dump_delay_range(*tx_dqs); + printram("TX DQ delay calibration results:\n"); + dump_delay_range(*tx_dq); + die("Could not calibrate transmit delays. Giving up"); + } + u8 result; + /************* TxDQS *************/ + dqs_tries++; + vx900_tx_dqs_delay_calib(); + vx900_read_delay_range(tx_dqs, CALIB_TxDQS); + + result = vx900_dram_check_calib_range(tx_dqs, DQSO_THRESHOLD); + if (result != DELAY_RANGE_GOOD) + continue; + + /************* TxDQ *************/ + /* FIXME: not sure if multiple page mode should be enabled here + * Vendor BIOS does it */ + pci_mod_config8(MCU, 0x69, 0, 0x01); + + dq_tries++; + vx900_tx_dq_delay_calib(); + vx900_read_delay_range(tx_dq, CALIB_TxDQ); + + result = vx900_dram_check_calib_range(tx_dq, DQO_THRESHOLD); + if (result != DELAY_RANGE_GOOD) + continue; + + /* At this point, our RAM should give correct read-backs for + * addresses under 64 MB. If it doesn't, it won't work */ + if (ram_check_noprint_nodie(1 << 20, 1 << 20)) { + /* No, our RAM is not working, try again */ + /* FIXME: Except that we have not yet told the MCU what + * the geometry of the DIMM is, hence we don't trust + * this test for now */ + ////continue; + } + /* Good. We should be able to use this DIMM */ + /* That's it. We're done */ + break; + } + if (n_tries > 1) + printram("Hmm, we had to try %lu times before our calibration " + "was good.\n", n_tries); +} + +/* + * The meat and potatoes of getting our MCU to operate the DIMMs properly. + * + * Thank you JEDEC for making us need configurable delays for each set of MD + * signals. + */ +static void vx900_dram_calibrate_delays(const ramctr_timing * ctrl, + const rank_layout * ranks) +{ + size_t i; + u8 val; + u8 dimm; + vx900_delay_calib delay_cal; + memset(&delay_cal, 0, sizeof(delay_cal)); + printram("Starting delay calibration\n"); + + /**** Read delay control ****/ + /* MD Input Data Push Timing Control; + * use values recommended in datasheet + * Setting this too low causes the Rx window to move below the range we + * need it so we can capture it with Rx_78_7f + * This causes Rx calibrations to be too close to 0, and Tx + * calibrations will fail. + * Setting this too high causes the window to move above the range. + */ + if (ctrl->tCK <= TCK_533MHZ) + val = 2; + else if (ctrl->tCK <= TCK_333MHZ) + val = 1; + else + val = 0; + val++; /* FIXME: vendor BIOS sets this to 3 */ + pci_mod_config8(MCU, 0x74, (0x03 << 1), ((val & 0x03) << 1)); + + /* FIXME: The vendor BIOS increases the MD input delay - WHY ? */ + pci_mod_config8(MCU, 0xef, (3 << 4), 3 << 4); + + /**** Write delay control ****/ + /* FIXME: The vendor BIOS does this, but WHY? + * See check_special_registers in VIA provided code. This value seems + * to depend on the DRAM frequency. + */ + /* Early DQ/DQS for write cycles */ + pci_mod_config8(MCU, 0x76, (3 << 2), 2 << 2); + /* FIXME: The vendor BIOS does this - Output preamble ? */ + pci_write_config8(MCU, 0x77, 0x10); + + /* Set BA[0/1/2] to [A17/18/19] */ + vx900_dram_set_ma_pin_map(VX900_MRS_MA_MAP); + /* Disable Multiple Page Mode - Set Rx69[0] to 0 */ + pci_mod_config8(MCU, 0x69, (1 << 0), 0x00); + + /* It's very important that we keep all ranks which are not calibrated + * mapped to VR3. Even if we disable them, if they are mapped to VR0 + * (the rank we use for calibrations), the calibrations may fail in + * unexpected ways. */ + vx900_pr_map_all_vr3(); + + /* We only really need to run the receive calibrations once. They are + * meant to account for signal travel differences in the internal paths + * of the MCU, so it doesn't really matter which rank we use for this. + * Differences between ranks will be accounted for in the transmit + * calibration. */ + for (i = 0; i < VX900_MAX_DIMM_SLOTS; i += 2) { + /* Do we have a valid DIMM? */ + if (ranks->phys_rank_size_mb[i] + + ranks->phys_rank_size_mb[i + 1] == 0) + continue; + /* Map the first rank of the DIMM to VR0 */ + vx900_map_pr_vr(2 * i, 0); + /* Only run on first rank, remember? */ + break; + } + vx900_dram_calibrate_recieve_delays(&delay_cal, + ranks->flags[i].pins_mirrored); + printram("RX DQS calibration results\n"); + dump_delay_range(delay_cal.rx_dqs); + + /* Enable multiple page mode for when calibrating transmit delays */ + pci_mod_config8(MCU, 0x69, 0, 1 << 1); + + /* + * Unlike the receive delays, we need to run the transmit calibration + * for each DIMM (not rank). We run the calibration on the even rank. + * The odd rank may have memory pins swapped, and this, it seems, + * confuses the calibration circuit. + */ + dimm = 0; + for (i = 0; i < VX900_MAX_DIMM_SLOTS; i++) { + /* Do we have a valid DIMM? */ + u32 dimm_size_mb = ranks->phys_rank_size_mb[2 * i] + + ranks->phys_rank_size_mb[2 * i + 1]; + if (dimm_size_mb == 0) + continue; + /* Map the first rank of the DIMM to VR0 */ + vx900_map_pr_vr(2 * i, 0); + vx900_dram_calibrate_transmit_delays(&(delay_cal.tx_dq[dimm]), + &(delay_cal.tx_dqs[dimm])); + /* We run this more than once, so dump delays for each DIMM */ + printram("Tx DQS calibration results\n"); + dump_delay_range(delay_cal.tx_dqs[dimm]); + printram("TX DQ delay calibration results:\n"); + dump_delay_range(delay_cal.tx_dq[dimm]); + /* Now move the DIMM back to VR3 */ + vx900_map_pr_vr(2 * i, 3); + /* We use dimm as a counter so that we fill tx_dq[] and tx_dqs[] + * results in order from 0, and do not leave any gaps */ + dimm++; + } + + /* When we have more dimms, we need to find a tx window with which all + * dimms can safely work */ + if (dimm > 1) { + vx900_dram_find_avg_delays(&delay_cal); + printram("Final delay values\n"); + printram("Tx DQS: "); + dump_delay(delay_cal.tx_dqs[0].avg); + printram("Tx DQ: "); + dump_delay(delay_cal.tx_dq[0].avg); + } + /* Write manual settings */ + pci_mod_config8(MCU, 0x75, 0, 0x01); + vx900_delay_calib_mode_select(CALIB_TxDQS, CALIB_MANUAL); + vx900_write_0x78_0x7f(delay_cal.tx_dqs[0].avg); + vx900_delay_calib_mode_select(CALIB_TxDQ, CALIB_MANUAL); + vx900_write_0x78_0x7f(delay_cal.tx_dq[0].avg); +} + +static void vx900_dram_set_refresh_counter(ramctr_timing * ctrl) +{ + u8 reg8; + /* Set DRAM refresh counter + * Based on a refresh counter of 0x61 at 400MHz */ + reg8 = (TCK_400MHZ * 0x61) / ctrl->tCK; + pci_write_config8(MCU, 0xc7, reg8); +} + +/* + * Here, we map each rank somewhere in our address space. We don't really care + * at this point if this will overlap the PCI config space. If needed, remapping + * is done in ramstage, where we actually know how much PCI space we actually + * need. + */ +static void vx900_dram_range(ramctr_timing * ctrl, rank_layout * ranks) +{ + size_t i, vrank = 0; + u8 reg8; + u32 ramsize_mb = 0, tolm_mb; + const u32 TOLM_3_5G = (7 << 29); + /* All unused physical ranks go to VR3. Otherwise, the MCU might be + * trying to read or write from unused ranks, or even worse, write some + * bits to the rank we want, and some to the unused ranks, even though + * they are disabled. Since VR3 is the last virtual rank to be used, we + * eliminate any ambiguities that the MCU may face. */ + vx900_pr_map_all_vr3(); + for (i = 0; i < VX900_MAX_MEM_RANKS; i++) { + u32 rank_size_mb = ranks->phys_rank_size_mb[i]; + if (!rank_size_mb) + continue; + + /* vvvvvvvvvv FIXME: Fix odd rank init vvvvvvvvvv */ + if ((i & 1)) { + printk(BIOS_EMERG, "I cannot initialize rank %li\n", i); + print_emerg("I have to disable it\n"); + continue; + } + /* ^^^^^^^^^^ FIXME: Fix odd rank init ^^^^^^^^^^ */ + + ranks->virt[vrank].start_addr = ramsize_mb; + ramsize_mb += rank_size_mb; + ranks->virt[vrank].end_addr = ramsize_mb; + + /* Rank memory range */ + reg8 = (ranks->virt[vrank].start_addr >> 6); + pci_write_config8(MCU, 0x48 + vrank, reg8); + reg8 = (ranks->virt[vrank].end_addr >> 6); + pci_write_config8(MCU, 0x40 + vrank, reg8); + + vx900_map_pr_vr(i, vrank); + + printram("Mapped Physical rank %u, to virtual rank %u\n" + " Start address: 0x%.10llx\n" + " End address: 0x%.10llx\n", + (int)i, (int)vrank, + (u64) ranks->virt[vrank].start_addr << 20, + (u64) ranks->virt[vrank].end_addr << 20); + /* Move on to next virtual rank */ + vrank++; + } + + /* Limit the Top of Low memory at 3.5G + * Not to worry, we'll set tolm in ramstage, once we have initialized + * all devices and know pci_tolm. */ + tolm_mb = min(ramsize_mb, TOLM_3_5G >> 20); + u16 reg_tolm = (tolm_mb << 4) & 0xfff0; + pci_mod_config16(MCU, 0x84, 0xfff0, reg_tolm); + + printram("Initialized %u virtual ranks, with a total size of %u MB\n", + (int)vrank, ramsize_mb); +} + +/* + * Here, we tell the memory controller how to treat a DIMM. This is an extremely + * important step. It tells the MCU how many address bits we have in each DIMM, + * and how to use them. This information is essential for the controller to + * understand the DIMM addressing, and write and read data in the correct place. + */ +static void vx900_dram_map_row_col_bank(dimm_info * dimms) +{ + u8 reg8, rcb_val, col_bits, max_row_bits; + size_t i; + /* Do we have 4Gbit chips? */ + /* FIXME: Implement this */ + + /* Do we have 8Gbit chips? */ + /* FIXME: Implement this */ + + max_row_bits = rcb_val = reg8 = 0; + for (i = 0; i < VX900_MAX_DIMM_SLOTS; i++) { + if (dimms->dimm[i].dram_type == SPD_MEMORY_TYPE_UNDEFINED) + continue; + + col_bits = dimms->dimm[i].col_bits; + + /* + * DDR3 always uses 3 bank address bits, and MA type 111b cannot + * be used due to chipset limitation. We are left with only two + * options, which we can choose based solely on the number of + * column address bits. + */ + if ((col_bits < 10) || (col_bits > 11)) { + printram("DIMM %ld has %d column address bits.\n", + i, col_bits); + die("Unsupported DIMM. Try booting without this DIMM"); + } + + rcb_val = col_bits - 5; + reg8 |= (rcb_val << ((i * 3) + 2)); + + /* */ + max_row_bits = max(max_row_bits, dimms->dimm[i].row_bits); + } + + printram("RCBA map (rx50) <- %.2x\n", reg8); + pci_write_config8(MCU, 0x50, reg8); + + printram("Houston, we have %d row address bits\n", max_row_bits); + /* FIXME: Do this properly */ + vx900_dram_map_pins(13, 14, 15, 17, 16); + +} + +/* + * Here, we set some final configuration bits, which should improve the + * performance of the memory slightly (arbitration, expiration counters, etc.) + * + * FIXME: We don't really do much else than the minimum to get the MCU properly + * configured. We don't yet do set the "performance-enhancing" bits referenced + * in the comment above. + */ +static void vx900_dram_write_final_config(ramctr_timing * ctrl) +{ + /* FIXME: These are quick cheats */ + + /* FIXME: Why are we doing this? */ + /* Tri-state MCSi# when rank is in self-refresh */ + pci_mod_config8(MCU, 0x99, 0, 0x0f); + + ////pci_write_config8(MCU, 0x69, 0xe7); + /* Enable paging mode and 8 page registers */ + pci_mod_config8(MCU, 0x69, 0, 0xe5); + ////pci_write_config8(MCU, 0x72, 0x0f); + + ////pci_write_config8(MCU, 0x97, 0xa4); /* self-refresh */ + ////pci_write_config8(MCU, 0x98, 0xba); /* self-refresh II */ + ////pci_write_config8(MCU, 0x9a, 0x80); /* self-refresh III */ + + /* Enable automatic triggering of short ZQ calibration */ + pci_write_config8(MCU, 0xc8, 0x80); + + /* And last but not least, Enable A20 line */ + outb(inb(0x92) | (1 << 1), 0x92); +} + +void vx900_init_dram_ddr3(const dimm_layout * dimm_addr) +{ + dimm_info dimm_prop; + ramctr_timing ctrl_prop; + rank_layout ranks; + device_t mcu; + + if (!ram_check_noprint_nodie(1 << 20, 1 << 20)) { + printram("RAM is already initialized. Skipping init\n"); + return; + } + /* Locate the Memory controller */ + mcu = pci_locate_device(PCI_ID(PCI_VENDOR_ID_VIA, + PCI_DEVICE_ID_VIA_VX900_MEMCTRL), 0); + + if (mcu == PCI_DEV_INVALID) { + die("Memory Controller not found\n"); + } + memset(&dimm_prop, 0, sizeof(dimm_prop)); + memset(&ctrl_prop, 0, sizeof(ctrl_prop)); + memset(&ranks, 0, sizeof(ranks)); + /* 1) Write some initial "safe" parameters */ + vx900_dram_write_init_config(); + /* 2) Get timing information from SPDs */ + dram_find_spds_ddr3(dimm_addr, &dimm_prop); + /* 3) Find lowest common denominator for all modules */ + dram_find_common_params(&dimm_prop, &ctrl_prop); + /* 4) Find the size of each memory rank */ + vx900_dram_phys_bank_range(&dimm_prop, &ranks); + /* 5) Set DRAM driving strength */ + vx900_dram_driving_ctrl(&dimm_prop); + /* 6) Set DRAM frequency and latencies */ + vx900_dram_timing(&ctrl_prop); + vx900_dram_freq(&ctrl_prop); + /* 7) Initialize the modules themselves */ + vx900_dram_ddr3_dimm_init(&ctrl_prop, &ranks); + /* 8) Set refresh counter based on DRAM frequency */ + vx900_dram_set_refresh_counter(&ctrl_prop); + /* 9) Calibrate receive and transmit delays */ + vx900_dram_calibrate_delays(&ctrl_prop, &ranks); + /* 10) Enable Physical to Virtual Rank mapping */ + vx900_dram_range(&ctrl_prop, &ranks); + /* 11) Map address bits to DRAM pins */ + vx900_dram_map_row_col_bank(&dimm_prop); + /* 99) Some final adjustments */ + vx900_dram_write_final_config(&ctrl_prop); + /* Take a dump */ + dump_pci_device(mcu); +} diff --git a/src/northbridge/via/vx900/vx900.h b/src/northbridge/via/vx900/vx900.h index c895e3d246..52c895c598 100644 --- a/src/northbridge/via/vx900/vx900.h +++ b/src/northbridge/via/vx900/vx900.h @@ -33,8 +33,8 @@ #define VX900_MAX_DIMM_SLOTS 2 #define VX900_MAX_MEM_RANKS 4 -#define min(a,b) a<b?a:b -#define max(a,b) a>b?a:b +#define min(a,b) (a<b?a:b) +#define max(a,b) (a>b?a:b) #include <arch/io.h> #include <device/pci.h> |