ps2ser.c
3.24 KB
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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/***********************************************************************
*
* (C) Copyright 2004
* DENX Software Engineering
* Wolfgang Denk, wd@denx.de
* All rights reserved.
*
* Simple 16550A serial driver
*
* Originally from linux source (drivers/char/ps2ser.c)
*
* Used by the PS/2 multiplexer driver (ps2mult.c)
*
***********************************************************************/
#include <common.h>
#ifdef CONFIG_PS2SERIAL
#include <asm/io.h>
#include <asm/atomic.h>
#include <ps2mult.h>
/* #define DEBUG */
#define PS2SER_BAUD 57600
static int ps2ser_getc_hw(void);
static void ps2ser_interrupt(void *dev_id);
extern struct serial_state rs_table[]; /* in serial.c */
static struct serial_state *state;
static u_char ps2buf[PS2BUF_SIZE];
static atomic_t ps2buf_cnt;
static int ps2buf_in_idx;
static int ps2buf_out_idx;
static inline unsigned int ps2ser_in(int offset)
{
return readb((unsigned long) state->iomem_base + offset);
}
static inline void ps2ser_out(int offset, int value)
{
writeb(value, (unsigned long) state->iomem_base + offset);
}
int ps2ser_init(void)
{
int quot;
unsigned cval;
state = rs_table + CONFIG_PS2SERIAL;
quot = state->baud_base / PS2SER_BAUD;
cval = 0x3; /* 8N1 - 8 data bits, no parity bits, 1 stop bit */
/* Set speed, enable interrupts, enable FIFO
*/
ps2ser_out(UART_LCR, cval | UART_LCR_DLAB);
ps2ser_out(UART_DLL, quot & 0xff);
ps2ser_out(UART_DLM, quot >> 8);
ps2ser_out(UART_LCR, cval);
ps2ser_out(UART_IER, UART_IER_RDI);
ps2ser_out(UART_MCR, UART_MCR_OUT2 | UART_MCR_DTR | UART_MCR_RTS);
ps2ser_out(UART_FCR,
UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
/* If we read 0xff from the LSR, there is no UART here
*/
if (ps2ser_in(UART_LSR) == 0xff) {
printf ("ps2ser.c: no UART found\n");
return -1;
}
irq_install_handler(state->irq, ps2ser_interrupt, NULL);
return 0;
}
void ps2ser_putc(int chr)
{
#ifdef DEBUG
printf(">>>> 0x%02x\n", chr);
#endif
while (!(ps2ser_in(UART_LSR) & UART_LSR_THRE));
ps2ser_out(UART_TX, chr);
}
static int ps2ser_getc_hw(void)
{
int res = -1;
if (ps2ser_in(UART_LSR) & UART_LSR_DR) {
res = (ps2ser_in(UART_RX));
}
return res;
}
int ps2ser_getc(void)
{
volatile int chr;
int flags;
#ifdef DEBUG
printf("<< ");
#endif
flags = disable_interrupts();
do {
if (atomic_read(&ps2buf_cnt) != 0) {
chr = ps2buf[ps2buf_out_idx++];
ps2buf_out_idx &= (PS2BUF_SIZE - 1);
atomic_dec(&ps2buf_cnt);
} else {
chr = ps2ser_getc_hw();
}
}
while (chr < 0);
if (flags) enable_interrupts();
#ifdef DEBUG
printf("0x%02x\n", chr);
#endif
return chr;
}
int ps2ser_check(void)
{
int flags;
flags = disable_interrupts();
ps2ser_interrupt(NULL);
if (flags) enable_interrupts();
return atomic_read(&ps2buf_cnt);
}
static void ps2ser_interrupt(void *dev_id)
{
int chr;
int iir;
do {
chr = ps2ser_getc_hw();
iir = ps2ser_in(UART_IIR);
if (chr < 0) continue;
if (atomic_read(&ps2buf_cnt) < PS2BUF_SIZE) {
ps2buf[ps2buf_in_idx++] = chr;
ps2buf_in_idx &= (PS2BUF_SIZE - 1);
atomic_inc(&ps2buf_cnt);
} else {
printf ("ps2ser.c: buffer overflow\n");
}
} while (iir & UART_IIR_RDI);
if (atomic_read(&ps2buf_cnt)) {
ps2mult_callback(atomic_read(&ps2buf_cnt));
}
}
#endif /* CONFIG_PS2SERIAL */