src/mainboard/amd/persimmon/dimmSpd.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2011 Advanced Micro Devices, Inc.
 *
 * 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; version 2 of the License.
 *
 * 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 "Porting.h"
#include "AGESA.h"
#include "amdlib.h"

AGESA_STATUS AmdMemoryReadSPD (UINT32 unused1, UINT32 unused2, AGESA_READ_SPD_PARAMS *info);
#define DIMENSION(array)(sizeof (array)/ sizeof (array [0]))

/*#pragma optimize ("", off) // for source level debug
*---------------------------------------------------------------------------
*
* SPD address table - porting required
*/

static const UINT8 spdAddressLookup [2] [2] [4] =	// socket, channel, dimm
{
// socket 0
	{
		{0xA0, 0xA2},	// channel 0 dimms
		{0x00, 0x00},	// channel 1 dimms
	},
	// socket 1
	{
		{0x00, 0x00},	// channel 0 dimms
		{0x00, 0x00},	// channel 1 dimms
	},
};

/*-----------------------------------------------------------------------------
 *
 * readSmbusByteData - read a single SPD byte from any offset
 */

static int readSmbusByteData (int iobase, int address, char *buffer, int offset)
{
	unsigned int 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 int readSmbusByte (int iobase, int address, char *buffer)
{
	unsigned int 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 int readspd (int iobase, int SmbusSlaveAddress, char *buffer, int count)
{
	int index, error;

	/* read the first byte using offset zero */
	error = readSmbusByteData (iobase, SmbusSlaveAddress, buffer, 0);
	if (error) return error;

	/* read the remaining bytes using auto-increment for speed */
	for (index = 1; index < count; index++) {
		error = readSmbusByte (iobase, SmbusSlaveAddress, &buffer [index]);
		if (error) return error;
	}

	return 0;
}

static void writePmReg (int reg, int data)
	{
	__outbyte (0xCD6, reg);
	__outbyte (0xCD7, data);
	}

static void setupFch (int ioBase)
{
	writePmReg (0x2D, ioBase >> 8);
	writePmReg (0x2C, ioBase | 1);
	writePmReg (0x29, 0x80);
	writePmReg (0x28, 0x61);
	__outbyte (ioBase + 0x0E, 66000000 / 400000 / 4); // set SMBus clock to 400 KHz
}

AGESA_STATUS AmdMemoryReadSPD (UINT32 unused1, UINT32 unused2, AGESA_READ_SPD_PARAMS *info)
{
	int spdAddress, ioBase;

	if (info->SocketId	 >= DIMENSION (spdAddressLookup		)) return AGESA_ERROR;
	if (info->MemChannelId >= DIMENSION (spdAddressLookup[0]	)) return AGESA_ERROR;
	if (info->DimmId		>= DIMENSION (spdAddressLookup[0][0])) return AGESA_ERROR;

	spdAddress = spdAddressLookup [info->SocketId] [info->MemChannelId] [info->DimmId];
	if (spdAddress == 0) return AGESA_ERROR;
	ioBase = 0xB00;
	setupFch (ioBase);
	return readspd (ioBase, spdAddress, (void *) info->Buffer, 128);
}