xref: /openbmc/u-boot/lib/time.c (revision 00a457b2)
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 static int notrace dm_timer_init(void)
45 {
46 	struct udevice *dev;
47 	int ret;
48 
49 	if (!gd->timer) {
50 		ret = uclass_first_device(UCLASS_TIMER, &dev);
51 		if (ret)
52 			return ret;
53 		if (!dev)
54 			return -ENODEV;
55 		gd->timer = dev;
56 	}
57 
58 	return 0;
59 }
60 
61 ulong notrace get_tbclk(void)
62 {
63 	int ret;
64 
65 	ret = dm_timer_init();
66 	if (ret)
67 		return ret;
68 
69 	return timer_get_rate(gd->timer);
70 }
71 
72 uint64_t notrace get_ticks(void)
73 {
74 	u64 count;
75 	int ret;
76 
77 	ret = dm_timer_init();
78 	if (ret)
79 		return ret;
80 
81 	ret = timer_get_count(gd->timer, &count);
82 	if (ret)
83 		return ret;
84 
85 	return count;
86 }
87 
88 #else /* !CONFIG_TIMER */
89 
90 uint64_t __weak notrace get_ticks(void)
91 {
92 	unsigned long now = timer_read_counter();
93 
94 	/* increment tbu if tbl has rolled over */
95 	if (now < gd->timebase_l)
96 		gd->timebase_h++;
97 	gd->timebase_l = now;
98 	return ((uint64_t)gd->timebase_h << 32) | gd->timebase_l;
99 }
100 
101 #endif /* CONFIG_TIMER */
102 
103 /* Returns time in milliseconds */
104 static uint64_t notrace tick_to_time(uint64_t tick)
105 {
106 	ulong div = get_tbclk();
107 
108 	tick *= CONFIG_SYS_HZ;
109 	do_div(tick, div);
110 	return tick;
111 }
112 
113 int __weak timer_init(void)
114 {
115 	return 0;
116 }
117 
118 /* Returns time in milliseconds */
119 ulong __weak get_timer(ulong base)
120 {
121 	return tick_to_time(get_ticks()) - base;
122 }
123 
124 unsigned long __weak notrace timer_get_us(void)
125 {
126 	return tick_to_time(get_ticks() * 1000);
127 }
128 
129 static uint64_t usec_to_tick(unsigned long usec)
130 {
131 	uint64_t tick = usec;
132 	tick *= get_tbclk();
133 	do_div(tick, 1000000);
134 	return tick;
135 }
136 
137 void __weak __udelay(unsigned long usec)
138 {
139 	uint64_t tmp;
140 
141 	tmp = get_ticks() + usec_to_tick(usec);	/* get current timestamp */
142 
143 	while (get_ticks() < tmp+1)	/* loop till event */
144 		 /*NOP*/;
145 }
146 
147 /* ------------------------------------------------------------------------- */
148 
149 void udelay(unsigned long usec)
150 {
151 	ulong kv;
152 
153 	do {
154 		WATCHDOG_RESET();
155 		kv = usec > CONFIG_WD_PERIOD ? CONFIG_WD_PERIOD : usec;
156 		__udelay (kv);
157 		usec -= kv;
158 	} while(usec);
159 }
160 
161 void mdelay(unsigned long msec)
162 {
163 	while (msec--)
164 		udelay(1000);
165 }
166