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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
enum smb_native_registers {
SMB_SDA = 0x00, SMB_STS = 0x01, SMB_CTRL_STS = 0x02,
SMB_CTRL1 = 0x03, SMB_ADD = 0x04, SMB_CTRL2 = 0x05,
SMB_CTRL3 = 0x06
};
enum smb_sts_bits {
SMB_STS_SLVSTP = (0x01 << 7), SMB_STS_SDAST = (0x01 << 6),
SMB_STS_BER = (0x01 << 5), SMB_STS_NEGACK = (0x01 << 4),
SMB_STS_STASTR = (0x01 << 3), SMB_STS_NMATCH = (0x01 << 2),
SMB_STS_MASTER = (0x01 << 1), SMB_STS_XMIT = (0x01 << 0)
};
enum smb_ctrl_sts_bits {
SMB_CSTS_TGSCL = (0x01 << 5), SMB_CSTS_TSDA = (0x01 << 4),
SMB_CSTS_GCMTCH = (0x01 << 3), SMB_CSTS_MATCH = (0x01 << 2),
SMB_CSTS_BB = (0x01 << 1), SMB_CSTS_BUSY = (0x01 << 0)
};
enum smb_ctrl1_bits {
SMB_CTRL1_STASTRE = (0x01 << 7), SMB_CTRL1_NMINTE = (0x01 << 6),
SMB_CTRL1_GCMEN = (0x01 << 5), SMB_CTRL1_ACK = (0x01 << 4),
SMB_CTRL1_RSVD = (0x01 << 3), SMB_CTRL1_INTEN = (0x01 << 2),
SMB_CTRL1_STOP = (0x01 << 1), SMB_CTRL1_START = (0x01 << 0)
};
enum smb_add_bits {
SMB_ADD_SAEN = (0x01 << 7)
};
enum smb_ctrl2_bits {
SMB_CTRL2_ENABLE = 0x01,
};
#define SMBUS_TIMEOUT (100*1000*10)
#define SMBUS_STATUS_MASK 0xfbff
static inline 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 int do_smbus_read_byte(unsigned smbus_io_base, unsigned char device, unsigned char address)
{
unsigned char val;
smbus_start_condition(smbus_io_base);
smbus_send_slave_address(smbus_io_base, device);
smbus_send_command(smbus_io_base, address);
smbus_start_condition(smbus_io_base);
smbus_send_slave_address(smbus_io_base, device | 0x01);
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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