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Adrian Alonso69535742015-09-02 13:54:16 -05001/*
2 * Copyright (C) 2015 Freescale Semiconductor, Inc.
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 *
6 * The file use ls102xa/timer.c as a reference.
7 */
8
9#include <common.h>
10#include <asm/io.h>
11#include <div64.h>
12#include <asm/arch/imx-regs.h>
13#include <asm/arch/sys_proto.h>
Stefano Babic552a8482017-06-29 10:16:06 +020014#include <asm/mach-imx/syscounter.h>
Adrian Alonso69535742015-09-02 13:54:16 -050015
16DECLARE_GLOBAL_DATA_PTR;
17
18/*
19 * This function is intended for SHORT delays only.
20 * It will overflow at around 10 seconds @ 400MHz,
21 * or 20 seconds @ 200MHz.
22 */
23unsigned long usec2ticks(unsigned long usec)
24{
25 ulong ticks;
26
27 if (usec < 1000)
28 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
29 else
30 ticks = ((usec / 10) * (get_tbclk() / 100000));
31
32 return ticks;
33}
34
35static inline unsigned long long tick_to_time(unsigned long long tick)
36{
37 unsigned long freq;
38
39 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
40
41 tick *= CONFIG_SYS_HZ;
42 do_div(tick, freq);
43
44 return tick;
45}
46
47static inline unsigned long long us_to_tick(unsigned long long usec)
48{
49 unsigned long freq;
50
51 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
52
53 usec = usec * freq + 999999;
54 do_div(usec, 1000000);
55
56 return usec;
57}
58
59int timer_init(void)
60{
61 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
62 unsigned long val, freq;
63
64 freq = CONFIG_SC_TIMER_CLK;
65 asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
66
67 writel(freq, &sctr->cntfid0);
68
69 /* Enable system counter */
70 val = readl(&sctr->cntcr);
71 val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
72 val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
73 writel(val, &sctr->cntcr);
74
75 gd->arch.tbl = 0;
76 gd->arch.tbu = 0;
77
78 return 0;
79}
80
81unsigned long long get_ticks(void)
82{
83 unsigned long long now;
84
85 asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
86
87 gd->arch.tbl = (unsigned long)(now & 0xffffffff);
88 gd->arch.tbu = (unsigned long)(now >> 32);
89
90 return now;
91}
92
93ulong get_timer_masked(void)
94{
95 return tick_to_time(get_ticks());
96}
97
98ulong get_timer(ulong base)
99{
100 return get_timer_masked() - base;
101}
102
103void __udelay(unsigned long usec)
104{
105 unsigned long long tmp;
106 ulong tmo;
107
108 tmo = us_to_tick(usec);
109 tmp = get_ticks() + tmo; /* get current timestamp */
110
111 while (get_ticks() < tmp) /* loop till event */
112 /*NOP*/;
113}
114
115/*
116 * This function is derived from PowerPC code (timebase clock frequency).
117 * On ARM it returns the number of timer ticks per second.
118 */
119ulong get_tbclk(void)
120{
121 unsigned long freq;
122
123 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
124
125 return freq;
126}