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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
#include <lib.h> /* Prototypes */
#include <arch/io.h>
/* Base Address */
#ifndef CONFIG_TTYS0_BASE
#define CONFIG_TTYS0_BASE 0x3f8
#endif
#ifndef CONFIG_TTYS0_BAUD
#define CONFIG_TTYS0_BAUD 115200
#endif
#if ((115200%CONFIG_TTYS0_BAUD) != 0)
#error Bad ttys0 baud rate
#endif
#ifndef CONFIG_TTYS0_DIV
#define CONFIG_TTYS0_DIV (115200/CONFIG_TTYS0_BAUD)
#endif
/* Line Control Settings */
#ifndef CONFIG_TTYS0_LCS
/* Set 8bit, 1 stop bit, no parity */
#define CONFIG_TTYS0_LCS 0x3
#endif
#define UART_LCS CONFIG_TTYS0_LCS
#if CONFIG_USE_PRINTK_IN_CAR == 0
/* Data */
#define UART_RBR 0x00
#define UART_TBR 0x00
/* Control */
#define UART_IER 0x01
#define UART_IIR 0x02
#define UART_FCR 0x02
#define UART_LCR 0x03
#define UART_MCR 0x04
#define UART_DLL 0x00
#define UART_DLM 0x01
/* Status */
#define UART_LSR 0x05
#define UART_MSR 0x06
#define UART_SCR 0x07
static int uart_can_tx_byte(void)
{
return inb(CONFIG_TTYS0_BASE + UART_LSR) & 0x20;
}
static void uart_wait_to_tx_byte(void)
{
while(!uart_can_tx_byte())
;
}
static void uart_wait_until_sent(void)
{
while(!(inb(CONFIG_TTYS0_BASE + UART_LSR) & 0x40))
;
}
static void uart_tx_byte(unsigned char data)
{
uart_wait_to_tx_byte();
outb(data, CONFIG_TTYS0_BASE + UART_TBR);
/* Make certain the data clears the fifos */
uart_wait_until_sent();
}
void uart_init(void)
{
/* disable interrupts */
outb(0x0, CONFIG_TTYS0_BASE + UART_IER);
/* enable fifo's */
outb(0x01, CONFIG_TTYS0_BASE + UART_FCR);
/* Set Baud Rate Divisor to 12 ==> 115200 Baud */
outb(0x80 | UART_LCS, CONFIG_TTYS0_BASE + UART_LCR);
#if CONFIG_USE_OPTION_TABLE == 1
static const unsigned char divisor[] = { 1,2,3,6,12,24,48,96 };
unsigned ttys0_div, ttys0_index;
ttys0_index = read_option(CMOS_VSTART_baud_rate, CMOS_VLEN_baud_rate, 0);
ttys0_index &= 7;
ttys0_div = divisor[ttys0_index];
outb(ttys0_div & 0xff, CONFIG_TTYS0_BASE + UART_DLL);
outb(0, CONFIG_TTYS0_BASE + UART_DLM);
#else
outb(CONFIG_TTYS0_DIV & 0xFF, CONFIG_TTYS0_BASE + UART_DLL);
outb((CONFIG_TTYS0_DIV >> 8) & 0xFF, CONFIG_TTYS0_BASE + UART_DLM);
#endif
outb(UART_LCS, CONFIG_TTYS0_BASE + UART_LCR);
}
#else
/* CONFIG_USE_PRINTK_IN_CAR == 1 */
extern void uart8250_init(unsigned base_port, unsigned divisor, unsigned lcs);
void uart_init(void)
{
#if CONFIG_USE_OPTION_TABLE == 1
static const unsigned char divisor[] = { 1,2,3,6,12,24,48,96 };
unsigned ttys0_div, ttys0_index;
ttys0_index = read_option(CMOS_VSTART_baud_rate, CMOS_VLEN_baud_rate, 0);
ttys0_index &= 7;
ttys0_div = divisor[ttys0_index];
uart8250_init(CONFIG_TTYS0_BASE, ttys0_div, UART_LCS);
#else
uart8250_init(CONFIG_TTYS0_BASE, CONFIG_TTYS0_DIV, UART_LCS);
#endif
}
#endif
|
