1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2014 Freescale Semiconductor, Inc.
4 */
5
6 #include <common.h>
7 #include <asm/io.h>
8 #include <div64.h>
9 #include <asm/arch/immap_ls102xa.h>
10 #include <asm/arch/clock.h>
11
12 DECLARE_GLOBAL_DATA_PTR;
13
14 /*
15 * This function is intended for SHORT delays only.
16 * It will overflow at around 10 seconds @ 400MHz,
17 * or 20 seconds @ 200MHz.
18 */
usec2ticks(unsigned long usec)19 unsigned long usec2ticks(unsigned long usec)
20 {
21 ulong ticks;
22
23 if (usec < 1000)
24 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
25 else
26 ticks = ((usec / 10) * (get_tbclk() / 100000));
27
28 return ticks;
29 }
30
tick_to_time(unsigned long long tick)31 static inline unsigned long long tick_to_time(unsigned long long tick)
32 {
33 unsigned long freq;
34
35 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
36
37 tick *= CONFIG_SYS_HZ;
38 do_div(tick, freq);
39
40 return tick;
41 }
42
us_to_tick(unsigned long long usec)43 static inline unsigned long long us_to_tick(unsigned long long usec)
44 {
45 unsigned long freq;
46
47 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
48
49 usec = usec * freq + 999999;
50 do_div(usec, 1000000);
51
52 return usec;
53 }
54
timer_init(void)55 int timer_init(void)
56 {
57 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
58 unsigned long ctrl, freq;
59 unsigned long long val;
60
61 /* Enable System Counter */
62 writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr);
63
64 freq = COUNTER_FREQUENCY;
65 asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
66
67 /* Set PL1 Physical Timer Ctrl */
68 ctrl = ARCH_TIMER_CTRL_ENABLE;
69 asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl));
70
71 /* Set PL1 Physical Comp Value */
72 val = TIMER_COMP_VAL;
73 asm("mcrr p15, 2, %Q0, %R0, c14" : : "r" (val));
74
75 gd->arch.tbl = 0;
76 gd->arch.tbu = 0;
77
78 return 0;
79 }
80
get_ticks(void)81 unsigned 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
get_timer(ulong base)93 unsigned long get_timer(ulong base)
94 {
95 return tick_to_time(get_ticks()) - base;
96 }
97
98 /* delay x useconds and preserve advance timstamp value */
__udelay(unsigned long usec)99 void __udelay(unsigned long usec)
100 {
101 unsigned long long start;
102 unsigned long tmo;
103
104 start = get_ticks(); /* get current timestamp */
105 tmo = us_to_tick(usec); /* convert usecs to ticks */
106
107 while ((get_ticks() - start) < tmo)
108 ; /* loop till time has passed */
109 }
110
111 /*
112 * This function is derived from PowerPC code (timebase clock frequency).
113 * On ARM it returns the number of timer ticks per second.
114 */
get_tbclk(void)115 unsigned long get_tbclk(void)
116 {
117 unsigned long freq;
118
119 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
120
121 return freq;
122 }
123