diff options
Diffstat (limited to 'src/southbridge/amd/cimx/sb900/smbus_spd.c')
| -rw-r--r-- | src/southbridge/amd/cimx/sb900/smbus_spd.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/southbridge/amd/cimx/sb900/smbus_spd.c b/src/southbridge/amd/cimx/sb900/smbus_spd.c new file mode 100644 index 0000000000..3fd4439985 --- /dev/null +++ b/src/southbridge/amd/cimx/sb900/smbus_spd.c @@ -0,0 +1,177 @@ +/***************************************************************************** + * + * Copyright (c) 2011, Advanced Micro Devices, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Advanced Micro Devices, Inc. nor the names of + * its contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL ADVANCED MICRO DEVICES, INC. BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + ***************************************************************************/ + +#include "Porting.h" +#include "AGESA.h" +#include "amdlib.h" + +#include <northbridge/amd/agesa/dimmSpd.h> + +#define SMBUS_BASE_ADDR 0xB00 + +STATIC +VOID +WritePmReg ( + IN UINT8 Reg, + IN UINT8 Data + ) +{ + __outbyte (0xCD6, Reg); + __outbyte (0xCD7, Data); +} +STATIC +VOID +SetupFch ( + IN UINT16 + IN IoBase + ) +{ + WritePmReg (0x2D, IoBase >> 8); + WritePmReg (0x2C, IoBase | 1); + WritePmReg (0x29, 0x80); + WritePmReg (0x28, 0x61); + /* set SMBus clock to 400 KHz */ + __outbyte (IoBase + 0x0E, 66000000 / 400000 / 4); +} + +/* + * + * ReadSmbusByteData - read a single SPD byte from any offset + * + */ + +STATIC +AGESA_STATUS +ReadSmbusByteData ( + IN UINT16 Iobase, + IN UINT8 Address, + OUT UINT8 *Buffer, + IN UINTN Offset + ) +{ + UINTN Status; + UINT64 Limit; + + Address |= 1; // set read bit + + __outbyte (Iobase + 0, 0xFF); // clear error status + __outbyte (Iobase + 1, 0x1F); // clear error status + __outbyte (Iobase + 3, Offset); // offset in eeprom + __outbyte (Iobase + 4, Address); // slave address and read bit + __outbyte (Iobase + 2, 0x48); // read byte command + + /* time limit to avoid hanging for unexpected error status (should never happen) */ + Limit = __rdtsc () + 2000000000 / 10; + for (;;) { + Status = __inbyte (Iobase); + if (__rdtsc () > Limit) break; + if ((Status & 2) == 0) continue; // SMBusInterrupt not set, keep waiting + if ((Status & 1) == 1) continue; // HostBusy set, keep waiting + break; + } + + Buffer [0] = __inbyte (Iobase + 5); + if (Status == 2) Status = 0; // check for done with no errors + return Status; + } + +/* + * + * ReadSmbusByte - read a single SPD byte from the default offset + * this function is faster function readSmbusByteData + * + */ + +STATIC +AGESA_STATUS +ReadSmbusByte ( + IN UINT16 Iobase, + IN UINT8 Address, + OUT UINT8 *Buffer + ) +{ + UINTN Status; + UINT64 Limit; + + __outbyte (Iobase + 0, 0xFF); // clear error status + __outbyte (Iobase + 2, 0x44); // read command + + // time limit to avoid hanging for unexpected error status + Limit = __rdtsc () + 2000000000 / 10; + for (;;) { + Status = __inbyte (Iobase); + if (__rdtsc () > Limit) break; + if ((Status & 2) == 0) continue; // SMBusInterrupt not set, keep waiting + if ((Status & 1) == 1) continue; // HostBusy set, keep waiting + break; + } + + Buffer [0] = __inbyte (Iobase + 5); + if (Status == 2) Status = 0; // check for done with no errors + return Status; +} + +/* + * + * ReadSpd - Read one or more SPD bytes from a DIMM. + * Start with offset zero and read sequentially. + * Optimization relies on autoincrement to avoid + * sending offset for every byte. + * Reads 128 bytes in 7-8 ms at 400 KHz. + * + */ + +STATIC +AGESA_STATUS +ReadSpd ( + IN UINT16 IoBase, + IN UINT8 SmbusSlaveAddress, + OUT UINT8 *Buffer, + IN UINTN Count + ) +{ + UINTN Index, Status; + + /* read the first byte using offset zero */ + Status = ReadSmbusByteData (IoBase, SmbusSlaveAddress, Buffer, 0); + if (Status) return Status; + + /* read the remaining bytes using auto-increment for speed */ + for (Index = 1; Index < Count; Index++){ + Status = ReadSmbusByte (IoBase, SmbusSlaveAddress, &Buffer [Index]); + if (Status) return Status; + } + return 0; +} + +int smbus_readSpd(int spdAddress, char *buf, size_t len) +{ + SetupFch (SMBUS_BASE_ADDR); + return ReadSpd (SMBUS_BASE_ADDR, spdAddress, (UINT8 *) buf, len); +} |