syscounter.c
2.39 KB
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
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2015 Freescale Semiconductor, Inc.
*
* The file use ls102xa/timer.c as a reference.
*/
#include <common.h>
#include <time.h>
#include <asm/io.h>
#include <div64.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/sys_proto.h>
#include <asm/mach-imx/syscounter.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* This function is intended for SHORT delays only.
* It will overflow at around 10 seconds @ 400MHz,
* or 20 seconds @ 200MHz.
*/
unsigned long usec2ticks(unsigned long usec)
{
ulong ticks;
if (usec < 1000)
ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
else
ticks = ((usec / 10) * (get_tbclk() / 100000));
return ticks;
}
static inline unsigned long long tick_to_time(unsigned long long tick)
{
unsigned long freq;
asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
tick *= CONFIG_SYS_HZ;
do_div(tick, freq);
return tick;
}
static inline unsigned long long us_to_tick(unsigned long long usec)
{
unsigned long freq;
asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
usec = usec * freq + 999999;
do_div(usec, 1000000);
return usec;
}
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
int timer_init(void)
{
struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
unsigned long val, freq;
freq = CONFIG_SC_TIMER_CLK;
asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
writel(freq, &sctr->cntfid0);
/* Enable system counter */
val = readl(&sctr->cntcr);
val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
writel(val, &sctr->cntcr);
gd->arch.tbl = 0;
gd->arch.tbu = 0;
return 0;
}
#endif
unsigned long long get_ticks(void)
{
unsigned long long now;
asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
gd->arch.tbl = (unsigned long)(now & 0xffffffff);
gd->arch.tbu = (unsigned long)(now >> 32);
return now;
}
ulong get_timer(ulong base)
{
return tick_to_time(get_ticks()) - base;
}
void __udelay(unsigned long usec)
{
unsigned long long tmp;
ulong tmo;
tmo = us_to_tick(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
unsigned long freq;
asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
return freq;
}