summaryrefslogtreecommitdiffstats
path: root/firmware/timer.c
blob: d15ba64443e0a037285911523161a96794ef0191 (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
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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Copyright (C) 2005 Jens Arnold
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/

#include <stdbool.h>
#include "config.h"
#include "cpu.h"
#include "system.h"
#include "timer.h"
#include "logf.h"

static int timer_prio = -1;
void (*pfn_timer)(void) = NULL;      /* timer callback */
void (*pfn_unregister)(void) = NULL; /* unregister callback */
#ifdef CPU_COLDFIRE
static int base_prescale;
#elif defined CPU_PP || CONFIG_CPU == PNX0101
static long cycles_new = 0;
#endif

/* interrupt handler */
#if CONFIG_CPU == SH7034
void IMIA4(void) __attribute__((interrupt_handler));
void IMIA4(void)
{
    if (pfn_timer != NULL)
        pfn_timer();
    and_b(~0x01, &TSR4); /* clear the interrupt */
}
#elif defined CPU_COLDFIRE
void TIMER1(void) __attribute__ ((interrupt_handler));
void TIMER1(void)
{
    if (pfn_timer != NULL)
        pfn_timer();
    TER1 = 0xff; /* clear all events */
}
#elif defined(CPU_PP)
void TIMER2(void)
{
    TIMER2_VAL; /* ACK interrupt */
    if (cycles_new > 0)
    {
        TIMER2_CFG = 0xc0000000 | (cycles_new - 1);
        cycles_new = 0;
    }
    if (pfn_timer != NULL)
    {
        cycles_new = -1;
        /* "lock" the variable, in case timer_set_period()
         * is called within pfn_timer() */
        pfn_timer();
        cycles_new = 0;
    }
}
#elif CONFIG_CPU == PNX0101
void TIMER1_ISR(void)
{
    if (cycles_new > 0)
    {
        TIMER1.load = cycles_new - 1;
        cycles_new = 0;
    }
    if (pfn_timer != NULL)
    {
        cycles_new = -1;
        /* "lock" the variable, in case timer_set_period()
         * is called within pfn_timer() */
        pfn_timer();
        cycles_new = 0;
    }
    TIMER1.clr = 1; /* clear the interrupt */
}
#endif /* CONFIG_CPU */

static bool timer_set(long cycles, bool start)
{
#if (CONFIG_CPU == SH7034) || defined(CPU_COLDFIRE)
    int phi = 0; /* bits for the prescaler */
    int prescale = 1;

    while (cycles > 0x10000)
    {   /* work out the smallest prescaler that makes it fit */
#if CONFIG_CPU == SH7034
        phi++;
#endif
        prescale *= 2;
        cycles >>= 1;
    }
#endif

#if CONFIG_CPU == PNX0101
    if (start)
    {
        if (pfn_unregister != NULL)
        {
            pfn_unregister();
            pfn_unregister = NULL;
        }
        TIMER1.ctrl &= ~0x80; /* disable the counter */
        TIMER1.ctrl |= 0x40;  /* reload after counting down to zero */
        TIMER1.ctrl &= ~0xc;  /* no prescaler */
        TIMER1.clr = 1;       /* clear an interrupt event */
    }
    if (start || (cycles_new == -1)) /* within isr, cycles_new is "locked" */
    {                                /* enable timer */
        TIMER1.load = cycles - 1;
        TIMER1.ctrl |= 0x80;        /* enable the counter */
    }
    else
        cycles_new = cycles;

    return true;
#elif CONFIG_CPU == SH7034
    if (prescale > 8)
        return false;

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

        and_b(~0x10, &TSTR); /* Stop the timer 4 */
        and_b(~0x10, &TSNC); /* No synchronization */
        and_b(~0x10, &TMDR); /* Operate normally */

        TIER4 = 0xF9;        /* Enable GRA match interrupt */
    }

    TCR4 = 0x20 | phi;   /* clear at GRA match, set prescaler */
    GRA4 = (unsigned short)(cycles - 1);
    if (start || (TCNT4 >= GRA4))
        TCNT4 = 0;
    and_b(~0x01, &TSR4); /* clear an eventual interrupt */

    return true;
#elif defined CPU_COLDFIRE
    if (prescale > 4096/CPUFREQ_MAX_MULT)
        return false;

    if (prescale > 256/CPUFREQ_MAX_MULT)
    {
        phi = 0x05;      /* prescale sysclk/16, timer enabled */
        prescale >>= 4;
    }
    else
        phi = 0x03;      /* prescale sysclk, timer enabled */
        
    base_prescale = prescale;
    prescale *= (cpu_frequency / CPU_FREQ);

    if (start)
    {
        if (pfn_unregister != NULL)
        {
            pfn_unregister();
            pfn_unregister = NULL;
        }
        phi &= ~1;       /* timer disabled at start */

        /* If it is already enabled, writing a 0 to the RST bit will clear
           the register, so we clear RST explicitly before writing the real
           data. */
        TMR1 = 0;
    }

    /* We are using timer 1 */
    TMR1 = 0x0018 | (unsigned short)phi | ((unsigned short)(prescale - 1) << 8);
    TRR1 = (unsigned short)(cycles - 1);
    if (start || (TCN1 >= TRR1))
        TCN1 = 0; /* reset the timer */
    TER1 = 0xff;  /* clear all events */

    return true;
#elif defined(CPU_PP)
    if (cycles > 0x20000000 || cycles < 2)
        return false;

    if (start)
    {
        if (pfn_unregister != NULL)
        {
            pfn_unregister();
            pfn_unregister = NULL;
        }
    }
    if (start || (cycles_new == -1))  /* within isr, cycles_new is "locked" */
        TIMER2_CFG = 0xc0000000 | (cycles - 1);    /* enable timer */
    else
        cycles_new = cycles;

    return true;
#elif (CONFIG_CPU == IMX31L)
    /* TODO */
#else
    return __TIMER_SET(cycles, start);
#endif /* CONFIG_CPU */
}

#ifdef CPU_COLDFIRE
void timers_adjust_prescale(int multiplier, bool enable_irq)
{
    /* tick timer */
    TMR0 = (TMR0 & 0x00ef)
         | ((unsigned short)(multiplier - 1) << 8)
         | (enable_irq ? 0x10 : 0);

    if (pfn_timer)
    {
        /* user timer */
        int prescale = base_prescale * multiplier;
        TMR1 = (TMR1 & 0x00ef)
             | ((unsigned short)(prescale - 1) << 8)
             | (enable_irq ? 0x10 : 0);
    }
}
#endif

/* Register a user timer, called every <cycles> TIMER_FREQ cycles */
bool timer_register(int reg_prio, void (*unregister_callback)(void),
                    long cycles, int int_prio, void (*timer_callback)(void))
{
    if (reg_prio <= timer_prio || cycles == 0)
        return false;

#if CONFIG_CPU == SH7034
    if (int_prio < 1 || int_prio > 15)
        return false;
#endif

    if (!timer_set(cycles, true))
        return false;
        
    pfn_timer = timer_callback;
    pfn_unregister = unregister_callback;
    timer_prio = reg_prio;

#if CONFIG_CPU == SH7034
    IPRD = (IPRD & 0xFF0F) | int_prio << 4;  /* interrupt priority */
    or_b(0x10, &TSTR); /* start timer 4 */
    return true;
#elif defined CPU_COLDFIRE
    ICR2 = 0x90;       /* interrupt on level 4.0 */
    and_l(~(1<<10), &IMR);
    TMR1 |= 1;         /* start timer */
    return true;
#elif defined(CPU_PP)
    /* unmask interrupt source */
    CPU_INT_EN = TIMER2_MASK;
    return true;
#elif CONFIG_CPU == PNX0101
    irq_set_int_handler(IRQ_TIMER1, TIMER1_ISR);
    irq_enable_int(IRQ_TIMER1);
    return true;
#elif CONFIG_CPU == IMX31L
    /* TODO */
#else
    return __TIMER_REGISTER(reg_prio, unregister_callback, cycles,
                            int_prio, timer_callback);
#endif
    /* Cover for targets that don't use all these */
    (void)reg_prio;
    (void)unregister_callback;
    (void)cycles;
    /* TODO: Implement for PortalPlayer and iFP (if possible) */
    (void)int_prio;
    (void)timer_callback; 
}

bool timer_set_period(long cycles)
{
    return timer_set(cycles, false);
}

void timer_unregister(void)
{
#if CONFIG_CPU == SH7034
    and_b(~0x10, &TSTR);    /* stop the timer 4 */
    IPRD = (IPRD & 0xFF0F); /* disable interrupt */
#elif defined CPU_COLDFIRE
    TMR1 = 0;               /* disable timer 1 */
    or_l((1<<10), &IMR);    /* disable interrupt */
#elif defined(CPU_PP)
    TIMER2_CFG = 0;         /* stop timer 2 */
    CPU_INT_CLR = TIMER2_MASK;
#elif CONFIG_CPU == PNX0101
    TIMER1.ctrl &= ~0x80;  /* disable timer 1 */
    irq_disable_int(IRQ_TIMER1);
#elif CONFIG_CPU == S3C2440
    __TIMER_UNREGISTER();
#endif
    pfn_timer = NULL;
    pfn_unregister = NULL;
    timer_prio = -1;
}