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/* SPDX-License-Identifier: GPL-2.0-only */
/* This file is part of the coreboot project. */
#include <amdblocks/acpimmio.h>
#include <device/pci_def.h>
#include <device/device.h>
#include <console/console.h>
/* warning: Porting.h includes an open #pragma pack(1) */
#include <Porting.h>
#include <AGESA.h>
#include <amdlib.h>
#include <northbridge/amd/agesa/dimmSpd.h>
/*-----------------------------------------------------------------------------
*
* 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;
printk(BIOS_SPEW, "-------------READING SPD-----------\n");
printk(BIOS_SPEW, "iobase: 0x%08X, SmbusSlave: 0x%08X, count: %d\n",
iobase, SmbusSlaveAddress, count);
/* read the first byte using offset zero */
error = readSmbusByteData (iobase, SmbusSlaveAddress, buffer, 0);
if (error) {
printk(BIOS_ERR, "-------------SPD READ ERROR-----------\n");
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) {
printk(BIOS_ERR, "-------------SPD READ ERROR-----------\n");
return error;
}
}
printk(BIOS_SPEW, "\n");
printk(BIOS_SPEW, "-------------FINISHED READING SPD-----------\n");
return 0;
}
static void setupFch (int ioBase)
{
pm_write16(0x2c, ioBase | 1);
__outbyte (ioBase + 0x0E, 66000000 / 400000 / 4); // set SMBus clock to 400 KHz
}
int hudson_readSpd(int spdAddress, char *buf, size_t len)
{
int ioBase = 0xB00;
setupFch (ioBase);
return readspd (ioBase, spdAddress, buf, len);
}
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