1 |
32985a29
|
laforge
|
/* Implementation of a virtual FIFO for OpenPCD
|
2 |
|
|
* (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
|
3 |
|
|
*
|
4 |
|
|
* This program is free software; you can redistribute it and/or modify
|
5 |
|
|
* it under the terms of the GNU General Public License as published by
|
6 |
|
|
* the Free Software Foundation; either version 2 of the License, or
|
7 |
|
|
* (at your option) any later version.
|
8 |
|
|
*
|
9 |
|
|
* This program is distributed in the hope that it will be useful,
|
10 |
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
11 |
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
12 |
|
|
* GNU General Public License for more details.
|
13 |
|
|
*
|
14 |
|
|
* You should have received a copy of the GNU General Public License
|
15 |
|
|
* along with this program; if not, write to the Free Software
|
16 |
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
17 |
|
|
*
|
18 |
|
|
*/
|
19 |
|
|
|
20 |
f57b548d
|
(no author)
|
|
21 |
f1202753
|
(no author)
|
#include "fifo.h"
|
22 |
f57b548d
|
(no author)
|
|
23 |
8a863d16
|
(no author)
|
#include <errno.h>
|
24 |
|
|
#include <string.h>
|
25 |
|
|
|
26 |
f57b548d
|
(no author)
|
#define FIFO_IRQ_LO 0x01
|
27 |
|
|
#define FIFO_IRQ_HI 0x02
|
28 |
|
|
#define FIFO_IRQ_OFLOW 0x04
|
29 |
|
|
|
30 |
|
|
/* returns number of data bytes present in the fifo */
|
31 |
|
|
int fifo_available(struct fifo *fifo)
|
32 |
|
|
{
|
33 |
|
|
if (fifo->producer > fifo->consumer)
|
34 |
|
|
return fifo->producer - fifo->consumer;
|
35 |
|
|
else
|
36 |
|
|
return (fifo->size - fifo->consumer) + fifo->producer;
|
37 |
|
|
}
|
38 |
|
|
|
39 |
|
|
void fifo_check_water(struct fifo *fifo)
|
40 |
|
|
{
|
41 |
|
|
int avail = fifo_available(fifo);
|
42 |
|
|
|
43 |
|
|
if (avail <= fifo->watermark)
|
44 |
8aaa856c
|
(no author)
|
fifo->irq |= FIFO_IRQ_LO;
|
45 |
f57b548d
|
(no author)
|
else
|
46 |
8aaa856c
|
(no author)
|
fifo->irq &= FIFO_IRQ_LO;
|
47 |
f57b548d
|
(no author)
|
|
48 |
|
|
if (fifo->size - avail >= fifo->watermark)
|
49 |
8aaa856c
|
(no author)
|
fifo->irq |= FIFO_IRQ_HI;
|
50 |
f57b548d
|
(no author)
|
else
|
51 |
8aaa856c
|
(no author)
|
fifo->irq &= FIFO_IRQ_HI;
|
52 |
f57b548d
|
(no author)
|
}
|
53 |
|
|
|
54 |
|
|
void fifo_check_raise_int(struct fifo *fifo)
|
55 |
|
|
{
|
56 |
|
|
if (fifo->irq & fifo->irq_en)
|
57 |
8a863d16
|
(no author)
|
fifo->callback(fifo, fifo->irq, fifo->cb_data);
|
58 |
f57b548d
|
(no author)
|
}
|
59 |
|
|
|
60 |
|
|
|
61 |
373c172a
|
Harald Welte
|
uint16_t fifo_data_put(struct fifo *fifo, uint16_t len, uint8_t *data)
|
62 |
f57b548d
|
(no author)
|
{
|
63 |
|
|
if (len > fifo_available(fifo)) {
|
64 |
8a863d16
|
(no author)
|
len = fifo_available(fifo);
|
65 |
f57b548d
|
(no author)
|
fifo->irq |= FIFO_IRQ_OFLOW;
|
66 |
|
|
}
|
67 |
|
|
|
68 |
|
|
if (len + fifo->producer <= fifo->size) {
|
69 |
|
|
/* easy case */
|
70 |
caf50003
|
(no author)
|
memcpy(&fifo->data[fifo->producer], data, len);
|
71 |
f57b548d
|
(no author)
|
fifo->producer += len;
|
72 |
|
|
} else {
|
73 |
|
|
/* difficult: wrap around */
|
74 |
373c172a
|
Harald Welte
|
uint16_t chunk_len;
|
75 |
f57b548d
|
(no author)
|
|
76 |
|
|
chunk_len = fifo->size - fifo->producer;
|
77 |
caf50003
|
(no author)
|
memcpy(&fifo->data[fifo->producer], data, chunk_len);
|
78 |
f57b548d
|
(no author)
|
|
79 |
caf50003
|
(no author)
|
memcpy(&fifo->data[0], data + chunk_len, len - chunk_len);
|
80 |
f57b548d
|
(no author)
|
fifo->producer = len - chunk_len;
|
81 |
|
|
}
|
82 |
|
|
|
83 |
|
|
fifo_check_water(fifo);
|
84 |
|
|
|
85 |
|
|
return len;
|
86 |
|
|
}
|
87 |
|
|
|
88 |
|
|
|
89 |
373c172a
|
Harald Welte
|
uint16_t fifo_data_get(struct fifo *fifo, uint16_t len, uint8_t *data)
|
90 |
f57b548d
|
(no author)
|
{
|
91 |
373c172a
|
Harald Welte
|
uint16_t avail = fifo_available(fifo);
|
92 |
f57b548d
|
(no author)
|
|
93 |
|
|
if (avail < len)
|
94 |
|
|
len = avail;
|
95 |
|
|
|
96 |
|
|
if (fifo->producer > fifo->consumer) {
|
97 |
|
|
/* easy case */
|
98 |
caf50003
|
(no author)
|
memcpy(data, &fifo->data[fifo->consumer], len);
|
99 |
f57b548d
|
(no author)
|
} else {
|
100 |
|
|
/* difficult case: wrap */
|
101 |
373c172a
|
Harald Welte
|
uint16_t chunk_len = fifo->size - fifo->consumer;
|
102 |
caf50003
|
(no author)
|
memcpy(data, &fifo->data[fifo->consumer], chunk_len);
|
103 |
|
|
memcpy(data+chunk_len, &fifo->data[0], len - chunk_len);
|
104 |
f57b548d
|
(no author)
|
}
|
105 |
|
|
|
106 |
|
|
fifo_check_water(fifo);
|
107 |
|
|
|
108 |
|
|
return len;
|
109 |
|
|
}
|
110 |
|
|
|
111 |
373c172a
|
Harald Welte
|
int fifo_init(struct fifo *fifo, uint16_t size,
|
112 |
|
|
void (*cb)(struct fifo *fifo, uint8_t event, void *data), void *cb_data)
|
113 |
f57b548d
|
(no author)
|
{
|
114 |
|
|
if (size > sizeof(fifo->data))
|
115 |
|
|
return -EINVAL;
|
116 |
|
|
|
117 |
|
|
memset(fifo->data, 0, sizeof(fifo->data));
|
118 |
|
|
fifo->size = size;
|
119 |
|
|
fifo->producer = fifo->consumer = 0;
|
120 |
|
|
fifo->watermark = 0;
|
121 |
8a863d16
|
(no author)
|
fifo->callback = cb;
|
122 |
f57b548d
|
(no author)
|
fifo->cb_data = cb_data;
|
123 |
|
|
|
124 |
|
|
return 0;
|
125 |
|
|
}
|