xref: /openbmc/u-boot/lib/time.c (revision 2399e401)
1 /*
2  * (C) Copyright 2000-2009
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <timer.h>
12 #include <watchdog.h>
13 #include <div64.h>
14 #include <asm/io.h>
15 
16 #ifndef CONFIG_WD_PERIOD
17 # define CONFIG_WD_PERIOD	(10 * 1000 * 1000)	/* 10 seconds default */
18 #endif
19 
20 DECLARE_GLOBAL_DATA_PTR;
21 
22 #ifdef CONFIG_SYS_TIMER_RATE
23 /* Returns tick rate in ticks per second */
24 ulong notrace get_tbclk(void)
25 {
26 	return CONFIG_SYS_TIMER_RATE;
27 }
28 #endif
29 
30 #ifdef CONFIG_SYS_TIMER_COUNTER
31 unsigned long notrace timer_read_counter(void)
32 {
33 #ifdef CONFIG_SYS_TIMER_COUNTS_DOWN
34 	return ~readl(CONFIG_SYS_TIMER_COUNTER);
35 #else
36 	return readl(CONFIG_SYS_TIMER_COUNTER);
37 #endif
38 }
39 #else
40 extern unsigned long __weak timer_read_counter(void);
41 #endif
42 
43 #ifdef CONFIG_TIMER
44 ulong notrace get_tbclk(void)
45 {
46 	if (!gd->timer) {
47 #ifdef CONFIG_TIMER_EARLY
48 		return timer_early_get_rate();
49 #else
50 		int ret;
51 
52 		ret = dm_timer_init();
53 		if (ret)
54 			return ret;
55 #endif
56 	}
57 
58 	return timer_get_rate(gd->timer);
59 }
60 
61 uint64_t notrace get_ticks(void)
62 {
63 	u64 count;
64 	int ret;
65 
66 	if (!gd->timer) {
67 #ifdef CONFIG_TIMER_EARLY
68 		return timer_early_get_count();
69 #else
70 		int ret;
71 
72 		ret = dm_timer_init();
73 		if (ret)
74 			return ret;
75 #endif
76 	}
77 
78 	ret = timer_get_count(gd->timer, &count);
79 	if (ret)
80 		return ret;
81 
82 	return count;
83 }
84 
85 #else /* !CONFIG_TIMER */
86 
87 uint64_t __weak notrace get_ticks(void)
88 {
89 	unsigned long now = timer_read_counter();
90 
91 	/* increment tbu if tbl has rolled over */
92 	if (now < gd->timebase_l)
93 		gd->timebase_h++;
94 	gd->timebase_l = now;
95 	return ((uint64_t)gd->timebase_h << 32) | gd->timebase_l;
96 }
97 
98 #endif /* CONFIG_TIMER */
99 
100 /* Returns time in milliseconds */
101 static uint64_t notrace tick_to_time(uint64_t tick)
102 {
103 	ulong div = get_tbclk();
104 
105 	tick *= CONFIG_SYS_HZ;
106 	do_div(tick, div);
107 	return tick;
108 }
109 
110 int __weak timer_init(void)
111 {
112 	return 0;
113 }
114 
115 /* Returns time in milliseconds */
116 ulong __weak get_timer(ulong base)
117 {
118 	return tick_to_time(get_ticks()) - base;
119 }
120 
121 unsigned long __weak notrace timer_get_us(void)
122 {
123 	return tick_to_time(get_ticks() * 1000);
124 }
125 
126 static uint64_t usec_to_tick(unsigned long usec)
127 {
128 	uint64_t tick = usec;
129 	tick *= get_tbclk();
130 	do_div(tick, 1000000);
131 	return tick;
132 }
133 
134 void __weak __udelay(unsigned long usec)
135 {
136 	uint64_t tmp;
137 
138 	tmp = get_ticks() + usec_to_tick(usec);	/* get current timestamp */
139 
140 	while (get_ticks() < tmp+1)	/* loop till event */
141 		 /*NOP*/;
142 }
143 
144 /* ------------------------------------------------------------------------- */
145 
146 void udelay(unsigned long usec)
147 {
148 	ulong kv;
149 
150 	do {
151 		WATCHDOG_RESET();
152 		kv = usec > CONFIG_WD_PERIOD ? CONFIG_WD_PERIOD : usec;
153 		__udelay (kv);
154 		usec -= kv;
155 	} while(usec);
156 }
157