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#define SMBUS_IO_BASE 0xf00
#define SMBHSTSTAT 0x0
#define SMBSLVSTAT 0x1
#define SMBHSTCTL 0x2
#define SMBHSTCMD 0x3
#define SMBXMITADD 0x4
#define SMBHSTDAT0 0x5
#define SMBHSTDAT1 0x6
#define SMBBLKDAT 0x7
#define SMBSLVCTL 0x8
#define SMBTRNSADD 0x9
#define SMBSLVDATA 0xa
#define SMLINK_PIN_CTL 0xe
#define SMBUS_PIN_CTL 0xf
/* Define register settings */
#define HOST_RESET 0xff
#define READ_CMD 0x01 // 1 in the 0 bit of SMBHSTADD states to READ
#define SMBUS_TIMEOUT (100*1000*10)
#define I2C_TRANS_CMD 0x40
#define CLOCK_SLAVE_ADDRESS 0x69
static void enable_smbus(void)
{
device_t dev;
unsigned char c;
int i;
/* Power management controller */
dev = pci_locate_device(PCI_ID(PCI_VENDOR_ID_VIA,
PCI_DEVICE_ID_VIA_8235), 0);
if (dev == PCI_DEV_INVALID) {
die("SMBUS controller not found\n");
}
// set IO base address to SMBUS_IO_BASE
pci_write_config16(dev, 0xd0, SMBUS_IO_BASE | 1);
// Enable SMBus
pci_write_config8(dev, 0xd2, (0x4 << 1) | 1);
/* make it work for I/O ...
*/
pci_write_config16(dev, 4, 1);
/* FIX for half baud rate problem */
/* let clocks and the like settle */
/* as yet arbitrary count - 1000 is too little 5000 works */
for(i = 0 ; i < 5000 ; i++)
outb(0x80,0x80);
/*
* The VT1211 serial port needs 48 mhz clock, on power up it is getting
* only 24 mhz, there is some mysterious device on the smbus that can
* fix this...this code below does it.
* */
outb(0xff, SMBUS_IO_BASE+SMBHSTSTAT);
outb(0x7f, SMBUS_IO_BASE+SMBHSTDAT0);
outb(0x83, SMBUS_IO_BASE+SMBHSTCMD);
outb(CLOCK_SLAVE_ADDRESS<<1 , SMBUS_IO_BASE+SMBXMITADD);
outb(8 | I2C_TRANS_CMD, SMBUS_IO_BASE+SMBHSTCTL);
for (;;) {
c = inb(SMBUS_IO_BASE+SMBHSTSTAT);
if ((c & 1) == 0)
break;
}
}
static inline void smbus_delay(void)
{
outb(0x80, 0x80);
}
static int smbus_wait_until_ready(void)
{
unsigned char c;
unsigned long loops;
loops = SMBUS_TIMEOUT;
do {
smbus_delay();
c = inb(SMBUS_IO_BASE + SMBHSTSTAT);
while((c & 1) == 1) {
print_debug("c is ");
print_debug_hex8(c);
print_debug("\n");
c = inb(SMBUS_IO_BASE + SMBHSTSTAT);
/* nop */
}
} while(--loops);
return loops?0:-1;
}
void smbus_reset(void)
{
outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT);
outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT);
outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT);
outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT);
smbus_wait_until_ready();
print_debug("After reset status ");
print_debug_hex8( inb(SMBUS_IO_BASE + SMBHSTSTAT));
print_debug("\n");
}
static int smbus_wait_until_done(void)
{
unsigned long loops;
unsigned char byte;
loops = SMBUS_TIMEOUT;
do {
smbus_delay();
byte = inb(SMBUS_IO_BASE + SMBHSTSTAT);
if (byte & 1)
break;
} while(--loops);
return loops?0:-1;
}
static void smbus_print_error(unsigned char host_status_register)
{
print_err("smbus_error: ");
print_err_hex8(host_status_register);
print_err("\n");
if (host_status_register & (1 << 4)) {
print_err("Interrup/SMI# was Failed Bus Transaction\n");
}
if (host_status_register & (1 << 3)) {
print_err("Bus Error\n");
}
if (host_status_register & (1 << 2)) {
print_err("Device Error\n");
}
if (host_status_register & (1 << 1)) {
print_err("Interrupt/SMI# was Successful Completion\n");
}
if (host_status_register & (1 << 0)) {
print_err("Host Busy\n");
}
}
/* SMBus routines borrowed from VIA's Trident Driver */
/* this works, so I am not going to touch it for now -- rgm */
static unsigned char smbus_read_byte(unsigned char devAdr,
unsigned char bIndex)
{
unsigned short i;
unsigned char bData;
unsigned char sts = 0;
/* clear host status */
outb(0xff, SMBUS_IO_BASE);
/* check SMBUS ready */
for ( i = 0; i < 0xFFFF; i++ )
if ( (inb(SMBUS_IO_BASE) & 0x01) == 0 )
break;
/* set host command */
outb(bIndex, SMBUS_IO_BASE+3);
/* set slave address */
outb((devAdr << 1) | 0x01, SMBUS_IO_BASE+4);
/* start */
outb(0x48, SMBUS_IO_BASE+2);
/* SMBUS Wait Ready */
for ( i = 0; i < 0xFFFF; i++ )
if ( ((sts = (inb(SMBUS_IO_BASE) & 0x1f)) & 0x01) == 0 )
break;
if ((sts & ~3) != 0) {
smbus_print_error(sts);
return 0;
}
bData=inb(SMBUS_IO_BASE+5);
return bData;
}
/* for reference, here is the fancier version which we will use at some
* point
*/
# if 0
int smbus_read_byte(unsigned device, unsigned address, unsigned char *result)
{
unsigned char host_status_register;
unsigned char byte;
reset();
smbus_wait_until_ready();
/* setup transaction */
/* disable interrupts */
outb(inb(SMBUS_IO_BASE + SMBHSTCTL) & (~1), SMBUS_IO_BASE + SMBHSTCTL);
/* set the device I'm talking too */
outb(((device & 0x7f) << 1) | 1, SMBUS_IO_BASE + SMBXMITADD);
/* set the command/address... */
outb(address & 0xFF, SMBUS_IO_BASE + SMBHSTCMD);
/* set up for a byte data read */
outb((inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xE3) | (0x2 << 2),
SMBUS_IO_BASE + SMBHSTCTL);
/* clear any lingering errors, so the transaction will run */
outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);
/* clear the data byte...*/
outb(0, SMBUS_IO_BASE + SMBHSTDAT0);
/* start the command */
outb((inb(SMBUS_IO_BASE + SMBHSTCTL) | 0x40),
SMBUS_IO_BASE + SMBHSTCTL);
/* poll for transaction completion */
smbus_wait_until_done();
host_status_register = inb(SMBUS_IO_BASE + SMBHSTSTAT);
/* Ignore the In Use Status... */
host_status_register &= ~(1 << 6);
/* read results of transaction */
byte = inb(SMBUS_IO_BASE + SMBHSTDAT0);
smbus_print_error(byte);
*result = byte;
return host_status_register != 0x02;
}
#endif
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