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//#include <device/smbus_def.h>
#define SMBUS_ERROR -1
#define SMBUS_WAIT_UNTIL_READY_TIMEOUT -2
#define SMBUS_WAIT_UNTIL_DONE_TIMEOUT -3
#define SMB_SDA 0x00
#define SMB_STS 0x01
#define SMB_CTRL_STS 0x02
#define SMB_CTRL1 0x03
#define SMB_ADD 0x04
#define SMB_CTRL2 0x05
#define SMB_CTRL3 0x06
#define SMB_STS_SLVSTP (0x01 << 7)
#define SMB_STS_SDAST (0x01 << 6)
#define SMB_STS_BER (0x01 << 5)
#define SMB_STS_NEGACK (0x01 << 4)
#define SMB_STS_STASTR (0x01 << 3)
#define SMB_STS_NMATCH (0x01 << 2)
#define SMB_STS_MASTER (0x01 << 1)
#define SMB_STS_XMIT (0x01 << 0)
#define SMB_CSTS_TGSCL (0x01 << 5)
#define SMB_CSTS_TSDA (0x01 << 4)
#define SMB_CSTS_GCMTCH (0x01 << 3)
#define SMB_CSTS_MATCH (0x01 << 2)
#define SMB_CSTS_BB (0x01 << 1)
#define SMB_CSTS_BUSY (0x01 << 0)
#define SMB_CTRL1_STASTRE (0x01 << 7)
#define SMB_CTRL1_NMINTE (0x01 << 6)
#define SMB_CTRL1_GCMEN (0x01 << 5)
#define SMB_CTRL1_ACK (0x01 << 4)
#define SMB_CTRL1_RSVD (0x01 << 3)
#define SMB_CTRL1_INTEN (0x01 << 2)
#define SMB_CTRL1_STOP (0x01 << 1)
#define SMB_CTRL1_START (0x01 << 0)
#define SMB_ADD_SAEN (0x01 << 7)
#define SMB_CTRL2_ENABLE 0x01
#define SMBUS_TIMEOUT (100*1000*10)
#define SMBUS_STATUS_MASK 0xfbff
#define SMBUS_IO_BASE 0x6000
static void smbus_delay(void)
{
outb(0x80, 0x80);
}
static int smbus_wait(unsigned smbus_io_base) {
unsigned long loops = SMBUS_TIMEOUT;
unsigned char val;
do {
smbus_delay();
val = inb(smbus_io_base + SMB_STS);
if ((val & SMB_STS_SDAST) != 0)
break;
if (val & (SMB_STS_BER | SMB_STS_NEGACK)) {
printk_debug("SMBUS WAIT ERROR %x\n", val);
return SMBUS_ERROR;
}
} while(--loops);
outb(0, smbus_io_base + SMB_STS);
return loops ? 0 : SMBUS_WAIT_UNTIL_READY_TIMEOUT;
}
static int smbus_write(unsigned smbus_io_base, unsigned char byte) {
outb(byte, smbus_io_base + SMB_SDA);
return smbus_wait(smbus_io_base);
}
/* generate a smbus start condition */
static int smbus_start_condition(unsigned smbus_io_base)
{
unsigned char val;
/* issue a START condition */
val = inb(smbus_io_base + SMB_CTRL1);
outb(val | SMB_CTRL1_START, smbus_io_base + SMB_CTRL1);
/* check for bus conflict */
val = inb(smbus_io_base + SMB_STS);
if ((val & SMB_STS_BER) != 0)
return SMBUS_ERROR;
return smbus_wait(smbus_io_base);
}
static int smbus_check_stop_condition(unsigned smbus_io_base)
{
unsigned char val;
unsigned long loops;
loops = SMBUS_TIMEOUT;
/* check for SDA status */
do {
smbus_delay();
val = inb(smbus_io_base + SMB_CTRL1);
if ((val & SMB_CTRL1_STOP) == 0) {
break;
}
} while(--loops);
return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT;
/* Make sure everything is cleared and ready to go */
val = inb(smbus_io_base + SMB_CTRL1);
outb(val & ~(SMB_CTRL1_STASTRE | SMB_CTRL1_NMINTE),
smbus_io_base + SMB_CTRL1);
outb(SMB_STS_BER | SMB_STS_NEGACK | SMB_STS_STASTR,
smbus_io_base + SMB_STS);
val = inb(smbus_io_base + SMB_CTRL_STS);
outb(val | SMB_CSTS_BB, smbus_io_base + SMB_CTRL_STS);
}
static int smbus_stop_condition(unsigned smbus_io_base)
{
unsigned char val;
val = inb(smbus_io_base + SMB_CTRL1);
outb(SMB_CTRL1_STOP, smbus_io_base + SMB_CTRL1);
return 0;
}
static int smbus_ack(unsigned smbus_io_base, int state)
{
unsigned char val = inb(smbus_io_base + SMB_CTRL1);
if (state)
outb(val | SMB_CTRL1_ACK, smbus_io_base + SMB_CTRL1);
else
outb(val & ~SMB_CTRL1_ACK, smbus_io_base + SMB_CTRL1);
return 0;
}
static int smbus_send_slave_address(unsigned smbus_io_base, unsigned char device)
{
unsigned char val;
/* send the slave address */
outb(device, smbus_io_base + SMB_SDA);
/* check for bus conflict and NACK */
val = inb(smbus_io_base + SMB_STS);
if (((val & SMB_STS_BER) != 0) ||
((val & SMB_STS_NEGACK) != 0)) {
printk_debug("SEND SLAVE ERROR (%x)\n", val);
return SMBUS_ERROR;
}
return smbus_wait(smbus_io_base);
}
static int smbus_send_command(unsigned smbus_io_base, unsigned char command)
{
unsigned char val;
/* send the command */
outb(command, smbus_io_base + SMB_SDA);
/* check for bus conflict and NACK */
val = inb(smbus_io_base + SMB_STS);
if (((val & SMB_STS_BER) != 0) ||
((val & SMB_STS_NEGACK) != 0))
return SMBUS_ERROR;
return smbus_wait(smbus_io_base);
}
static void _doread(unsigned smbus_io_base, unsigned char device,
unsigned char address, unsigned char *data, int count)
{
int ret;
int index = 0;
unsigned char val;
if ((ret = smbus_check_stop_condition(smbus_io_base)))
goto err;
index++;
if ((ret = smbus_start_condition(smbus_io_base)))
goto err;
index++; /* 2 */
if ((ret = smbus_send_slave_address(smbus_io_base, device)))
goto err;
index++;
if ((ret = smbus_send_command(smbus_io_base, address)))
goto err;
index++;
if ((ret = smbus_start_condition(smbus_io_base)))
goto err;
/* Clear the ack for multiple byte reads */
smbus_ack(smbus_io_base, (count == 1) ? 1 : 0);
index++;
if ((ret = smbus_send_slave_address(smbus_io_base, device | 0x01)))
goto err;
while(count) {
/* Set the ACK if this is the next to last byte */
smbus_ack(smbus_io_base, (count == 2) ? 1 : 0);
/* Set the stop bit if this is the last byte to read */
if (count == 1)
smbus_stop_condition(smbus_io_base);
val = inb(smbus_io_base + SMB_SDA);
*data++ = val;
if (count > 1) {
int ret = smbus_wait(smbus_io_base);
if (ret)
return ret;
}
count--;
}
return;
err:
printk_debug("SMBUS READ ERROR (%d): %d\n", index, ret);
}
static unsigned char do_smbus_read_byte(unsigned smbus_io_base,
unsigned char device,
unsigned char address)
{
unsigned char val = 0;
_doread(smbus_io_base, device, address, &val, sizeof(val));
return val;
}
static unsigned short do_smbus_read_word(unsigned smbus_io_base,
unsigned char device, unsigned char address)
{
unsigned short val = 0;
_doread(smbus_io_base, device, address, (unsigned char *) &val,
sizeof(val));
return val;
}
static int _dowrite(unsigned smbus_io_base, unsigned char device,
unsigned char address, unsigned char *data, int count) {
int ret;
if ((ret = smbus_check_stop_condition(smbus_io_base)))
goto err;
if ((ret = smbus_start_condition(smbus_io_base)))
goto err;
if ((ret = smbus_send_slave_address(smbus_io_base, device)))
goto err;
if ((ret = smbus_send_command(smbus_io_base, address)))
goto err;
while(count) {
if ((ret = smbus_write(smbus_io_base, *data++)))
goto err;
count--;
}
smbus_stop_condition(smbus_io_base);
return 0;
err:
printk_debug("SMBUS WRITE ERROR: %d\n", ret);
return -1;
}
static int do_smbus_write_byte(unsigned smbus_io_base, unsigned char device,
unsigned char address, unsigned char data)
{
return _dowrite(smbus_io_base, device, address,
(unsigned char *) &data, 1);
}
static int do_smbus_write_word(unsigned smbus_io_base, unsigned char device, unsigned char address,
unsigned short data)
{
return _dowrite(smbus_io_base, device ,address, (unsigned char *) &data, 2);
}
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