summaryrefslogtreecommitdiffstats
path: root/firmware/target/arm/tms320dm320/timer-dm320.c
blob: ff9beab96c507aa7fadd31d63a961c5b1bfe3a4d (plain)
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
/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Copyright (C) 2007 by Karl Kurbjun
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/

#include "config.h"
#include "cpu.h"
#include "system.h"
#include "timer.h"
#include "logf.h"

/* GPB0/TOUT0 should already have been configured as output so that pin
  should not be a functional pin and TIMER0 output unseen there */
void TIMER0(void)
{
    IO_INTC_IRQ0 = INTR_IRQ0_TMR0; /* clear TIMER0 interrupt */
    if (pfn_timer != NULL)
        pfn_timer();
}

bool __timer_set(long cycles, bool start)
{
    int oldlevel;
    unsigned int divider=cycles, prescaler=0;

    if(cycles<1)
        return false;

    oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
    
    IO_CLK_MOD2 |= CLK_MOD2_TMR0; //enable TIMER0 clock!!!!!!!!!

    IO_TIMER0_TMMD = CONFIG_TIMER0_TMMD_STOP;

    if (start && pfn_unregister != NULL)
    {
        pfn_unregister();
        pfn_unregister = NULL;
    }

    oldlevel = disable_irq_save();

    /* Increase prescale values starting from 0 to make the cycle count fit */
    while(divider>65535 && prescaler<1024)
    {
        prescaler++;
        divider=cycles/(prescaler+1);
    }

    IO_TIMER0_TMPRSCL = prescaler;
    IO_TIMER0_TMDIV = divider;

    restore_irq(oldlevel);

    return true;
}

static void stop_timer(void)
{
    IO_INTC_EINT0 &= ~INTR_EINT0_TMR0; //disable TIMER0 interrupt

    IO_INTC_IRQ0 = INTR_IRQ0_TMR0; //clear TIMER0 interrupt
    
    IO_TIMER0_TMMD = CONFIG_TIMER0_TMMD_STOP;
    
    IO_CLK_MOD2 &= ~CLK_MOD2_TMR0; //disable TIMER0 clock
}

bool __timer_register(void)
{
    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
    
    stop_timer();
    
    IO_CLK_MOD2 |= CLK_MOD2_TMR0; //enable TIMER0 clock!!!!!!!!!

    /* Turn Timer0 to Free Run mode */
    IO_TIMER0_TMMD = CONFIG_TIMER0_TMMD_FREE_RUN;

    IO_INTC_EINT0 |= INTR_EINT0_TMR0; //enable TIMER0 interrupt

    restore_interrupt(oldstatus);

    return true;
}

void __timer_unregister(void)
{
    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
    stop_timer();
    restore_interrupt(oldstatus);
}