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
16 DECLARE_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 */
usec2ticks(unsigned long usec)23 unsigned 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
tick_to_time(unsigned long long tick)35 static 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
us_to_tick(unsigned long long usec)47 static 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
timer_init(void)59 int 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 = 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
get_ticks(void)85 unsigned 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
get_timer(ulong base)97 unsigned 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 */
__udelay(unsigned long usec)103 void __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 */
get_tbclk(void)119 unsigned 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