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/*
* Enable the serial evices on the VIA
*/
/* The base address is 0x15c, 0x2e, depending on config bytes */
#define SIO_BASE 0x3f0
#define SIO_DATA SIO_BASE+1
static void
vt8231_writesuper(uint8_t reg, uint8_t val) {
outb(reg, SIO_BASE);
outb(val, SIO_DATA);
}
static void
vt8231_writesiobyte(uint16_t reg, uint8_t val) {
outb(val, reg);
}
static void
vt8231_writesioword(uint16_t reg, uint16_t val) {
outw(val, reg);
}
/* regs we use: 85, and the southbridge devfn is defined by the
mainboard
*/
static void
enable_vt8231_serial(void) {
unsigned long x;
uint8_t c;
device_t dev;
outb(6, 0x80);
dev = pci_locate_device(PCI_ID(0x1106,0x8231), 0);
if (dev == PCI_DEV_INVALID) {
outb(7, 0x80);
die("Serial controller not found\r\n");
}
/* first, you have to enable the superio and superio config.
put a 6 reg 80
*/
c = pci_read_config8(dev, 0x50);
c |= 6;
pci_write_config8(dev, 0x50, c);
outb(2, 0x80);
// now go ahead and set up com1.
// set address
vt8231_writesuper(0xf4, 0xfe);
// enable serial out
vt8231_writesuper(0xf2, 7);
// That's it for the sio stuff.
// movl $SUPERIOCONFIG, %eax
// movb $9, %dl
// PCI_WRITE_CONFIG_BYTE
// set up reg to set baud rate.
vt8231_writesiobyte(0x3fb, 0x80);
// Set 115 kb
vt8231_writesioword(0x3f8, 1);
// Set 9.6 kb
// WRITESIOWORD(0x3f8, 12)
// now set no parity, one stop, 8 bits
vt8231_writesiobyte(0x3fb, 3);
// now turn on RTS, DRT
vt8231_writesiobyte(0x3fc, 3);
// Enable interrupts
vt8231_writesiobyte(0x3f9, 0xf);
// should be done. Dump a char for fun.
vt8231_writesiobyte(0x3f8, 48);
}
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