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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2010 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.
*/
#include <stdint.h>
#include <console/console.h>
#include <device/smbus_host.h>
#include <amdblocks/acpimmio.h>
#include <soc/southbridge.h>
/*
* Between 1-10 seconds, We should never timeout normally
* Longer than this is just painful when a timeout condition occurs.
*/
#define SMBUS_TIMEOUT (100 * 1000 * 10)
static u8 controller_read8(uintptr_t base, u8 reg)
{
switch (base) {
case ACPIMMIO_SMBUS_BASE:
return smbus_read8(reg);
case ACPIMMIO_ASF_BASE:
return asf_read8(reg);
default:
printk(BIOS_ERR, "Error attempting to read SMBus at address 0x%lx\n",
base);
}
return 0xff;
}
static void controller_write8(uintptr_t base, u8 reg, u8 val)
{
switch (base) {
case ACPIMMIO_SMBUS_BASE:
smbus_write8(reg, val);
break;
case ACPIMMIO_ASF_BASE:
asf_write8(reg, val);
break;
default:
printk(BIOS_ERR, "Error attempting to write SMBus at address 0x%lx\n",
base);
}
}
static int smbus_wait_until_ready(uintptr_t mmio)
{
u32 loops;
loops = SMBUS_TIMEOUT;
do {
u8 val;
val = controller_read8(mmio, SMBHSTSTAT);
val &= SMBHST_STAT_VAL_BITS;
if (val == 0) { /* ready now */
return 0;
}
controller_write8(mmio, SMBHSTSTAT, val);
} while (--loops);
return -2; /* time out */
}
static int smbus_wait_until_done(uintptr_t mmio)
{
u32 loops;
loops = SMBUS_TIMEOUT;
do {
u8 val;
val = controller_read8(mmio, SMBHSTSTAT);
val &= SMBHST_STAT_VAL_BITS; /* mask off reserved bits */
if (val & SMBHST_STAT_ERROR_BITS)
return -5; /* error */
if (val == SMBHST_STAT_NOERROR) {
controller_write8(mmio, SMBHSTSTAT, val); /* clr sts */
return 0;
}
} while (--loops);
return -3; /* timeout */
}
int do_smbus_recv_byte(uintptr_t mmio, u8 device)
{
u8 byte;
if (smbus_wait_until_ready(mmio) < 0)
return -2; /* not ready */
/* set the device I'm talking to */
controller_write8(mmio, SMBHSTADDR, ((device & 0x7f) << 1) | 1);
byte = controller_read8(mmio, SMBHSTCTRL);
byte &= ~SMBHST_CTRL_MODE_BITS; /* Clear [4:2] */
byte |= SMBHST_CTRL_STRT | SMBHST_CTRL_BTE_RW; /* set mode, start */
controller_write8(mmio, SMBHSTCTRL, byte);
/* poll for transaction completion */
if (smbus_wait_until_done(mmio) < 0)
return -3; /* timeout or error */
/* read results of transaction */
byte = controller_read8(mmio, SMBHSTDAT0);
return byte;
}
int do_smbus_send_byte(uintptr_t mmio, u8 device, u8 val)
{
u8 byte;
if (smbus_wait_until_ready(mmio) < 0)
return -2; /* not ready */
/* set the command... */
controller_write8(mmio, SMBHSTDAT0, val);
/* set the device I'm talking to */
controller_write8(mmio, SMBHSTADDR, ((device & 0x7f) << 1) | 0);
byte = controller_read8(mmio, SMBHSTCTRL);
byte &= ~SMBHST_CTRL_MODE_BITS; /* Clear [4:2] */
byte |= SMBHST_CTRL_STRT | SMBHST_CTRL_BTE_RW; /* set mode, start */
controller_write8(mmio, SMBHSTCTRL, byte);
/* poll for transaction completion */
if (smbus_wait_until_done(mmio) < 0)
return -3; /* timeout or error */
return 0;
}
int do_smbus_read_byte(uintptr_t mmio, u8 device, u8 address)
{
u8 byte;
if (smbus_wait_until_ready(mmio) < 0)
return -2; /* not ready */
/* set the command/address... */
controller_write8(mmio, SMBHSTCMD, address & 0xff);
/* set the device I'm talking to */
controller_write8(mmio, SMBHSTADDR, ((device & 0x7f) << 1) | 1);
byte = controller_read8(mmio, SMBHSTCTRL);
byte &= ~SMBHST_CTRL_MODE_BITS; /* Clear [4:2] */
byte |= SMBHST_CTRL_STRT | SMBHST_CTRL_BDT_RW; /* set mode, start */
controller_write8(mmio, SMBHSTCTRL, byte);
/* poll for transaction completion */
if (smbus_wait_until_done(mmio) < 0)
return -3; /* timeout or error */
/* read results of transaction */
byte = controller_read8(mmio, SMBHSTDAT0);
return byte;
}
int do_smbus_write_byte(uintptr_t mmio, u8 device, u8 address, u8 val)
{
u8 byte;
if (smbus_wait_until_ready(mmio) < 0)
return -2; /* not ready */
/* set the command/address... */
controller_write8(mmio, SMBHSTCMD, address & 0xff);
/* set the device I'm talking to */
controller_write8(mmio, SMBHSTADDR, ((device & 0x7f) << 1) | 0);
/* output value */
controller_write8(mmio, SMBHSTDAT0, val);
byte = controller_read8(mmio, SMBHSTCTRL);
byte &= ~SMBHST_CTRL_MODE_BITS; /* Clear [4:2] */
byte |= SMBHST_CTRL_STRT | SMBHST_CTRL_BDT_RW; /* set mode, start */
controller_write8(mmio, SMBHSTCTRL, byte);
/* poll for transaction completion */
if (smbus_wait_until_done(mmio) < 0)
return -3; /* timeout or error */
return 0;
}
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