1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2015 Freescale Semiconductor, Inc.
4 *
5 * The file use ls102xa/timer.c as a reference.
6 */
7
8 #include <common.h>
9 #include <init.h>
10 #include <time.h>
11 #include <asm/global_data.h>
12 #include <asm/io.h>
13 #include <div64.h>
14 #include <asm/arch/imx-regs.h>
15 #include <asm/arch/sys_proto.h>
16 #include <asm/mach-imx/syscounter.h>
17 #include <linux/delay.h>
18
19 DECLARE_GLOBAL_DATA_PTR;
20
21 /*
22 * This function is intended for SHORT delays only.
23 * It will overflow at around 10 seconds @ 400MHz,
24 * or 20 seconds @ 200MHz.
25 */
usec2ticks(unsigned long usec)26 unsigned long usec2ticks(unsigned long usec)
27 {
28 ulong ticks;
29
30 if (usec < 1000)
31 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
32 else
33 ticks = ((usec / 10) * (get_tbclk() / 100000));
34
35 return ticks;
36 }
37
tick_to_time(unsigned long long tick)38 static inline unsigned long long tick_to_time(unsigned long long tick)
39 {
40 unsigned long freq;
41
42 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
43
44 tick *= CONFIG_SYS_HZ;
45 do_div(tick, freq);
46
47 return tick;
48 }
49
us_to_tick(unsigned long long usec)50 static inline unsigned long long us_to_tick(unsigned long long usec)
51 {
52 unsigned long freq;
53
54 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
55
56 usec = usec * freq + 999999;
57 do_div(usec, 1000000);
58
59 return usec;
60 }
61
62 #if !CONFIG_IS_ENABLED(SKIP_LOWLEVEL_INIT)
timer_init(void)63 int timer_init(void)
64 {
65 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
66 unsigned long val, freq;
67
68 freq = CFG_SC_TIMER_CLK;
69 asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
70
71 writel(freq, &sctr->cntfid0);
72
73 /* Enable system counter */
74 val = readl(&sctr->cntcr);
75 val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
76 val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
77 writel(val, &sctr->cntcr);
78
79 gd->arch.tbl = 0;
80 gd->arch.tbu = 0;
81
82 gd->arch.timer_rate_hz = freq;
83 return 0;
84 }
85 #endif
86
get_ticks(void)87 unsigned long long get_ticks(void)
88 {
89 unsigned long long now;
90
91 asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
92
93 gd->arch.tbl = (unsigned long)(now & 0xffffffff);
94 gd->arch.tbu = (unsigned long)(now >> 32);
95
96 return now;
97 }
98
get_timer(ulong base)99 ulong get_timer(ulong base)
100 {
101 return tick_to_time(get_ticks()) - base;
102 }
103
timer_get_boot_us(void)104 ulong timer_get_boot_us(void)
105 {
106 if (!gd->arch.timer_rate_hz)
107 timer_init();
108
109 return tick_to_time(get_ticks());
110 }
111
__udelay(unsigned long usec)112 void __udelay(unsigned long usec)
113 {
114 unsigned long long tmp;
115 ulong tmo;
116
117 tmo = us_to_tick(usec);
118 tmp = get_ticks() + tmo; /* get current timestamp */
119
120 while (get_ticks() < tmp) /* loop till event */
121 /*NOP*/;
122 }
123
124 /*
125 * This function is derived from PowerPC code (timebase clock frequency).
126 * On ARM it returns the number of timer ticks per second.
127 */
get_tbclk(void)128 ulong get_tbclk(void)
129 {
130 unsigned long freq;
131
132 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
133
134 return freq;
135 }
136