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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
static void smbus_delay(void)
{
outb(0x80, 0x80);
}
/* generate a smbus start condition */
static int smbus_start_condition(unsigned smbus_io_base)
{
unsigned char val;
unsigned long loops;
loops = SMBUS_TIMEOUT;
/* 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;
/* check for SDA status */
do {
smbus_delay();
val = inw(smbus_io_base + SMB_STS);
if ((val & SMB_STS_SDAST) != 0) {
break;
}
} while(--loops);
return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT;
}
static int smbus_send_slave_address(unsigned smbus_io_base, unsigned char device)
{
unsigned char val;
unsigned long loops;
loops = SMBUS_TIMEOUT;
/* 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))
return SMBUS_ERROR;
/* check for SDA status */
do {
smbus_delay();
val = inw(smbus_io_base + SMB_STS);
if ((val & SMB_STS_SDAST) != 0) {
break;
}
} while(--loops);
return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT;
}
static int smbus_send_command(unsigned smbus_io_base, unsigned char command)
{
unsigned char val;
unsigned long loops;
loops = SMBUS_TIMEOUT;
/* 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;
/* check for SDA status */
do {
smbus_delay();
val = inw(smbus_io_base + SMB_STS);
if ((val & SMB_STS_SDAST) != 0) {
break;
}
} while(--loops);
return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT;
}
static unsigned char do_smbus_read_byte(unsigned smbus_io_base, unsigned char device, unsigned char address)
{
unsigned char val;
if (smbus_start_condition(smbus_io_base) < 0)
print_debug("smbus error 1");
if (smbus_send_slave_address(smbus_io_base, device) < 0)
print_debug("smbus error 2");
if (smbus_send_command(smbus_io_base, address) < 0)
print_debug("smbus error 3");
if (smbus_start_condition(smbus_io_base) < 0)
print_debug("smbus error 4");
if (smbus_send_slave_address(smbus_io_base, device | 0x01))
print_debug("smbus error 5");
val = inb(smbus_io_base + SMB_CTRL1);
outb(val | SMB_CTRL1_ACK, smbus_io_base + SMB_CTRL1);
return inb(smbus_io_base + SMB_SDA);
}
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