blob: 2863f359e7a6240aa38c73818fe8fa8c1afbaa9d (
plain) (
blame)
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
|
/*
* Copyright (c) 2014 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#include <bsp.h>
#include <leon.h>
#include <rtems/counter.h>
static volatile struct gptimer_regs *leon3_cpu_counter_gpt;
void leon3_cpu_counter_initialize(void)
{
struct ambapp_dev *adev;
int idx = 1;
volatile struct gptimer_regs *gpt;
unsigned new_prescaler = 8;
unsigned prescaler;
uint32_t frequency;
adev = (void *) ambapp_for_each(
&ambapp_plb,
OPTIONS_ALL | OPTIONS_APB_SLVS,
VENDOR_GAISLER,
GAISLER_GPTIMER,
ambapp_find_by_idx,
&idx
);
if (adev == NULL) {
rtems_fatal(RTEMS_FATAL_SOURCE_BSP_SPECIFIC, LEON3_FATAL_CPU_COUNTER_INIT);
}
gpt = (volatile struct gptimer_regs *) DEV_TO_APB(adev)->start;
prescaler = gpt->scaler_reload + 1;
gpt->scaler_reload = new_prescaler - 1;
gpt->timer[0].reload = 0xffffffff;
gpt->timer[0].ctrl = LEON3_GPTIMER_EN | LEON3_GPTIMER_RL
| LEON3_GPTIMER_LD;
leon3_cpu_counter_gpt = gpt;
/* Assume that GRMON initialized the timer to 1MHz */
frequency = UINT32_C(1000000) * (prescaler / new_prescaler);
rtems_counter_initialize_converter(frequency);
}
CPU_Counter_ticks _CPU_Counter_read(void)
{
volatile struct gptimer_regs *gpt = leon3_cpu_counter_gpt;
return 0U - gpt->timer[0].value;
}
|
