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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2005 Yinghai Lu <yinghailu@gmail.com>
* Copyright (C) 2009 coresystems GmbH
* Copyright (C) 2013 Vladimir Serbinenko
*
* 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 <arch/io.h>
#include <device/smbus_def.h>
#include <stdlib.h>
#include "smbus.h"
/* I801 command constants */
#define I801_QUICK (0 << 2)
#define I801_BYTE (1 << 2)
#define I801_BYTE_DATA (2 << 2)
#define I801_WORD_DATA (3 << 2)
#define I801_BLOCK_DATA (5 << 2)
#define I801_I2C_BLOCK_DATA (6 << 2) /* ICH5 and later */
/* I801 Host Control register bits */
#define SMBHSTCNT_INTREN (1 << 0)
#define SMBHSTCNT_KILL (1 << 1)
#define SMBHSTCNT_LAST_BYTE (1 << 5)
#define SMBHSTCNT_START (1 << 6)
#define SMBHSTCNT_PEC_EN (1 << 7) /* ICH3 and later */
/* I801 Hosts Status register bits */
#define SMBHSTSTS_BYTE_DONE (1 << 7)
#define SMBHSTSTS_INUSE_STS (1 << 6)
#define SMBHSTSTS_SMBALERT_STS (1 << 5)
#define SMBHSTSTS_FAILED (1 << 4)
#define SMBHSTSTS_BUS_ERR (1 << 3)
#define SMBHSTSTS_DEV_ERR (1 << 2)
#define SMBHSTSTS_INTR (1 << 1)
#define SMBHSTSTS_HOST_BUSY (1 << 0)
#define SMBUS_TIMEOUT (10 * 1000 * 100)
#define SMBUS_BLOCK_MAXLEN 32
static void smbus_delay(void)
{
inb(0x80);
}
static int smbus_wait_until_ready(u16 smbus_base)
{
unsigned int loops = SMBUS_TIMEOUT;
unsigned char byte;
do {
smbus_delay();
if (--loops == 0)
break;
byte = inb(smbus_base + SMBHSTSTAT);
} while (byte & SMBHSTSTS_HOST_BUSY);
return loops ? 0 : -1;
}
static int smbus_wait_until_done(u16 smbus_base)
{
unsigned int loops = SMBUS_TIMEOUT;
unsigned char byte;
do {
smbus_delay();
if (--loops == 0)
break;
byte = inb(smbus_base + SMBHSTSTAT);
} while ((byte & SMBHSTSTS_HOST_BUSY)
|| (byte & ~(SMBHSTSTS_INUSE_STS | SMBHSTSTS_HOST_BUSY)) == 0);
return loops ? 0 : -1;
}
static int smbus_wait_until_active(u16 smbus_base)
{
unsigned long loops;
loops = SMBUS_TIMEOUT;
do {
unsigned char val;
smbus_delay();
val = inb(smbus_base + SMBHSTSTAT);
if ((val & SMBHSTSTS_HOST_BUSY)) {
break;
}
} while (--loops);
return loops ? 0 : -1;
}
int do_smbus_read_byte(unsigned int smbus_base, u8 device,
unsigned int address)
{
unsigned char status;
unsigned char byte;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
/* Set up transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN,
smbus_base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((device & 0x7f) << 1) | 1, smbus_base + SMBXMITADD);
/* Set the command/address... */
outb(address & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a byte data read */
outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | I801_BYTE_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* Clear the data byte... */
outb(0, smbus_base + SMBHSTDAT0);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
smbus_base + SMBHSTCTL);
/* poll for it to start */
if (smbus_wait_until_active(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT;
/* Poll for transaction completion */
if (smbus_wait_until_done(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
status = inb(smbus_base + SMBHSTSTAT);
/* Ignore the "In Use" status... */
status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS);
/* Read results of transaction */
byte = inb(smbus_base + SMBHSTDAT0);
if (status != SMBHSTSTS_INTR)
return SMBUS_ERROR;
return byte;
}
int do_smbus_write_byte(unsigned int smbus_base, u8 device,
unsigned int address, unsigned int data)
{
unsigned char status;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
/* Set up transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN,
smbus_base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((device & 0x7f) << 1) & ~0x01, smbus_base + SMBXMITADD);
/* Set the command/address... */
outb(address & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a byte data read */
outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | I801_BYTE_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* Clear the data byte... */
outb(data, smbus_base + SMBHSTDAT0);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
smbus_base + SMBHSTCTL);
/* poll for it to start */
if (smbus_wait_until_active(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT;
/* Poll for transaction completion */
if (smbus_wait_until_done(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
status = inb(smbus_base + SMBHSTSTAT);
/* Ignore the "In Use" status... */
status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS);
/* Read results of transaction */
if (status != SMBHSTSTS_INTR)
return SMBUS_ERROR;
return 0;
}
int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd,
unsigned int max_bytes, u8 *buf)
{
u8 status;
int slave_bytes;
int bytes_read = 0;
unsigned int loops = SMBUS_TIMEOUT;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
max_bytes = MIN(SMBUS_BLOCK_MAXLEN, max_bytes);
/* Set up transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN,
smbus_base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((device & 0x7f) << 1) | 1, smbus_base + SMBXMITADD);
/* Set the command/address... */
outb(cmd & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a block data read */
outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_BLOCK_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* Reset number of bytes to transfer so we notice later it
* was really updated with the transaction. */
outb(0, smbus_base + SMBHSTDAT0);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
smbus_base + SMBHSTCTL);
/* poll for it to start */
if (smbus_wait_until_active(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT;
/* Poll for transaction completion */
do {
loops--;
status = inb(smbus_base + SMBHSTSTAT);
if (status & (SMBHSTSTS_FAILED | /* FAILED */
SMBHSTSTS_BUS_ERR | /* BUS ERR */
SMBHSTSTS_DEV_ERR)) /* DEV ERR */
return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) { /* Byte done */
if (bytes_read < max_bytes) {
*buf++ = inb(smbus_base + SMBBLKDAT);
bytes_read++;
}
/* Engine internally completes the transaction
* and clears HOST_BUSY flag once the byte count
* from slave is reached.
*/
outb(status, smbus_base + SMBHSTSTAT);
}
} while ((status & SMBHSTSTS_HOST_BUSY) && loops);
/* Post-check we received complete message. */
slave_bytes = inb(smbus_base + SMBHSTDAT0);
if (bytes_read < slave_bytes)
return SMBUS_ERROR;
return bytes_read;
}
int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd,
const unsigned int bytes, const u8 *buf)
{
u8 status;
int bytes_sent = 0;
unsigned int loops = SMBUS_TIMEOUT;
if (bytes > SMBUS_BLOCK_MAXLEN)
return SMBUS_ERROR;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
/* Set up transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN,
smbus_base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((device & 0x7f) << 1) & ~0x01, smbus_base + SMBXMITADD);
/* Set the command/address... */
outb(cmd & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a block data write */
outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_BLOCK_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* set number of bytes to transfer */
outb(bytes, smbus_base + SMBHSTDAT0);
/* Send first byte from buffer, bytes_sent increments after
* hardware acknowledges it.
*/
outb(*buf++, smbus_base + SMBBLKDAT);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
smbus_base + SMBHSTCTL);
/* poll for it to start */
if (smbus_wait_until_active(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT;
/* Poll for transaction completion */
do {
loops--;
status = inb(smbus_base + SMBHSTSTAT);
if (status & (SMBHSTSTS_FAILED | /* FAILED */
SMBHSTSTS_BUS_ERR | /* BUS ERR */
SMBHSTSTS_DEV_ERR)) /* DEV ERR */
return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) {
bytes_sent++;
if (bytes_sent < bytes)
outb(*buf++, smbus_base + SMBBLKDAT);
/* Engine internally completes the transaction
* and clears HOST_BUSY flag once the byte count
* has been reached.
*/
outb(status, smbus_base + SMBHSTSTAT);
}
} while ((status & SMBHSTSTS_HOST_BUSY) && loops);
if (bytes_sent < bytes)
return SMBUS_ERROR;
return bytes_sent;
}
/* Only since ICH5 */
int do_i2c_block_read(unsigned int smbus_base, u8 device,
unsigned int offset, u32 bytes, u8 *buf)
{
u8 status;
int bytes_read = 0;
unsigned int loops = SMBUS_TIMEOUT;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
/* Set upp transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & SMBHSTCNT_INTREN,
smbus_base + SMBHSTCTL);
/* Set the device I'm talking to */
outb((device & 0x7f) << 1, smbus_base + SMBXMITADD);
/* device offset */
outb(offset, smbus_base + SMBHSTDAT1);
/* Set up for a i2c block data read */
outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_I2C_BLOCK_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
smbus_base + SMBHSTCTL);
/* poll for it to start */
if (smbus_wait_until_active(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT;
/* Poll for transaction completion */
do {
loops--;
status = inb(smbus_base + SMBHSTSTAT);
if (status & (SMBHSTSTS_FAILED | /* FAILED */
SMBHSTSTS_BUS_ERR | /* BUS ERR */
SMBHSTSTS_DEV_ERR)) /* DEV ERR */
return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) {
*buf = inb(smbus_base + SMBBLKDAT);
buf++;
bytes_read++;
if (--bytes == 1) {
/* indicate that next byte is the last one */
outb(inb(smbus_base + SMBHSTCTL)
| SMBHSTCNT_LAST_BYTE,
smbus_base + SMBHSTCTL);
}
outb(status, smbus_base + SMBHSTSTAT);
}
} while ((status & SMBHSTSTS_HOST_BUSY) && loops);
return bytes_read;
}
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