1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
* Enable the serial devices 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 vt8235_writepnpaddr(uint8_t val)
{
outb(val, 0x2e);
outb(val, 0xeb);
}
static void vt8235_writepnpdata(uint8_t val)
{
outb(val, 0x2f);
outb(val, 0xeb);
}
static void vt8235_writesiobyte(uint16_t reg, uint8_t val)
{
outb(val, reg);
}
static void vt8235_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_vt8235_serial(void)
{
// turn on pnp
vt8235_writepnpaddr(0x87);
vt8235_writepnpaddr(0x87);
// now go ahead and set up com1.
// set address
vt8235_writepnpaddr(0x7);
vt8235_writepnpdata(0x2);
// enable serial out
vt8235_writepnpaddr(0x30);
vt8235_writepnpdata(0x1);
// serial port 1 base address (FEh)
vt8235_writepnpaddr(0x60);
vt8235_writepnpdata(0xfe);
// serial port 1 IRQ (04h)
vt8235_writepnpaddr(0x70);
vt8235_writepnpdata(0x4);
// serial port 1 control
vt8235_writepnpaddr(0xf0);
vt8235_writepnpdata(0x2);
// turn of pnp
vt8235_writepnpaddr(0xaa);
// set up reg to set baud rate.
vt8235_writesiobyte(0x3fb, 0x80);
// Set 115 kb
vt8235_writesioword(0x3f8, 1);
// Set 9.6 kb
// WRITESIOWORD(0x3f8, 12)
// now set no parity, one stop, 8 bits
vt8235_writesiobyte(0x3fb, 3);
// now turn on RTS, DRT
vt8235_writesiobyte(0x3fc, 3);
// Enable interrupts
vt8235_writesiobyte(0x3f9, 0xf);
// should be done. Dump a char for fun.
vt8235_writesiobyte(0x3f8, 48);
}
|
