1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright 2014 Freescale Semiconductor, Inc.
4 */
5
6#include <common.h>
7#include <init.h>
8#include <time.h>
9#include <asm/global_data.h>
10#include <asm/io.h>
11#include <div64.h>
12#include <asm/arch/immap_ls102xa.h>
13#include <asm/arch/clock.h>
14#include <linux/delay.h>
15
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 ctrl, freq;
63	unsigned long long val;
64
65	/* Enable System Counter */
66	writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr);
67
68	freq = CONFIG_COUNTER_FREQUENCY;
69	asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
70
71	/* Set PL1 Physical Timer Ctrl */
72	ctrl = ARCH_TIMER_CTRL_ENABLE;
73	asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl));
74
75	/* Set PL1 Physical Comp Value */
76	val = TIMER_COMP_VAL;
77	asm("mcrr p15, 2, %Q0, %R0, c14" : : "r" (val));
78
79	gd->arch.tbl = 0;
80	gd->arch.tbu = 0;
81
82	return 0;
83}
84
85unsigned long long get_ticks(void)
86{
87	unsigned long long now;
88
89	asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
90
91	gd->arch.tbl = (unsigned long)(now & 0xffffffff);
92	gd->arch.tbu = (unsigned long)(now >> 32);
93
94	return now;
95}
96
97unsigned long get_timer(ulong base)
98{
99	return tick_to_time(get_ticks()) - base;
100}
101
102/* delay x useconds and preserve advance timstamp value */
103void __udelay(unsigned long usec)
104{
105	unsigned long long start;
106	unsigned long tmo;
107
108	start = get_ticks();			/* get current timestamp */
109	tmo = us_to_tick(usec);			/* convert usecs to ticks */
110
111	while ((get_ticks() - start) < tmo)
112		;				/* loop till time has passed */
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 */
119unsigned long 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}
127