| rev |
line source |
|
nuclear@0
|
1 /*
|
|
nuclear@7
|
2 gbasys - a gameboy advance hardware abstraction library
|
|
nuclear@7
|
3 Copyright (C) 2004-2014 John Tsiombikas <nuclear@member.fsf.org>
|
|
nuclear@0
|
4
|
|
nuclear@7
|
5 This program is free software: you can redistribute it and/or modify
|
|
nuclear@0
|
6 it under the terms of the GNU General Public License as published by
|
|
nuclear@7
|
7 the Free Software Foundation, either version 3 of the License, or
|
|
nuclear@0
|
8 (at your option) any later version.
|
|
nuclear@0
|
9
|
|
nuclear@0
|
10 This program is distributed in the hope that it will be useful,
|
|
nuclear@0
|
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
nuclear@0
|
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
nuclear@0
|
13 GNU General Public License for more details.
|
|
nuclear@0
|
14
|
|
nuclear@0
|
15 You should have received a copy of the GNU General Public License
|
|
nuclear@7
|
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
nuclear@0
|
17 */
|
|
nuclear@0
|
18 #include <limits.h>
|
|
nuclear@0
|
19 #include "intr.h"
|
|
nuclear@0
|
20 #include "signal.h"
|
|
nuclear@0
|
21
|
|
nuclear@0
|
22 /* prescalar selection based on the system clock (16.78MHz) */
|
|
nuclear@0
|
23 #define TIMER_CNTL_CLK 0
|
|
nuclear@0
|
24 #define TIMER_CNTL_CLK64 1
|
|
nuclear@0
|
25 #define TIMER_CNTL_CLK256 2
|
|
nuclear@0
|
26 #define TIMER_CNTL_CLK1024 3
|
|
nuclear@0
|
27
|
|
nuclear@0
|
28 /* control bits */
|
|
nuclear@0
|
29 #define TIMER_CNTL_COUNTUP 4
|
|
nuclear@0
|
30 #define TIMER_CNTL_INTR 0x40
|
|
nuclear@0
|
31 #define TIMER_CNTL_ENABLE 0x80
|
|
nuclear@0
|
32
|
|
nuclear@0
|
33 static void timer_intr_handler(void);
|
|
nuclear@0
|
34
|
|
nuclear@0
|
35 volatile static unsigned short *reg_timer[] = {(void*)0x4000100, (void*)0x4000104, (void*)0x4000108, (void*)0x400010c};
|
|
nuclear@0
|
36 static unsigned short *reg_timer_cntl[] = {(void*)0x4000102, (void*)0x4000106, (void*)0x400010a, (void*)0x400010e};
|
|
nuclear@0
|
37
|
|
nuclear@0
|
38 static unsigned long milli_sec;
|
|
nuclear@0
|
39 static unsigned long alarm_val;
|
|
nuclear@0
|
40
|
|
nuclear@0
|
41 void enable_timer(int timer) {
|
|
nuclear@0
|
42 *reg_timer_cntl[timer] |= TIMER_CNTL_ENABLE;
|
|
nuclear@0
|
43 }
|
|
nuclear@0
|
44
|
|
nuclear@0
|
45 void disable_timer(int timer) {
|
|
nuclear@0
|
46 *reg_timer_cntl[timer] &= ~TIMER_CNTL_ENABLE;
|
|
nuclear@0
|
47 }
|
|
nuclear@0
|
48
|
|
nuclear@0
|
49 void reset_msec_timer(void) {
|
|
nuclear@0
|
50 *reg_timer_cntl[0] &= ~TIMER_CNTL_ENABLE;
|
|
nuclear@0
|
51 interrupt(INTR_TIMER0, timer_intr_handler);
|
|
nuclear@0
|
52 milli_sec = 0;
|
|
nuclear@0
|
53 *reg_timer[0] = USHRT_MAX - 16779;
|
|
nuclear@0
|
54 *reg_timer_cntl[0] = TIMER_CNTL_INTR | TIMER_CNTL_ENABLE;
|
|
nuclear@0
|
55 unmask(INTR_TIMER0);
|
|
nuclear@0
|
56 }
|
|
nuclear@0
|
57
|
|
nuclear@0
|
58
|
|
nuclear@0
|
59 unsigned long get_millisec(void) {
|
|
nuclear@0
|
60 return milli_sec;
|
|
nuclear@0
|
61 }
|
|
nuclear@0
|
62
|
|
nuclear@0
|
63 unsigned int alarm(unsigned int seconds) {
|
|
nuclear@0
|
64 unsigned int prev = alarm_val;
|
|
nuclear@0
|
65 alarm_val = seconds * 1000;
|
|
nuclear@0
|
66 }
|
|
nuclear@0
|
67
|
|
nuclear@0
|
68 static void timer_intr_handler(void) {
|
|
nuclear@0
|
69 milli_sec++;
|
|
nuclear@0
|
70
|
|
nuclear@0
|
71 if(alarm_val > 0) {
|
|
nuclear@0
|
72 if(!--alarm_val) raise(SIGALRM);
|
|
nuclear@0
|
73 }
|
|
nuclear@0
|
74 }
|
