xref: /openbmc/u-boot/arch/arm/mach-rmobile/timer.c (revision 0649cd0d)
1 /*
2  * (C) Copyright 2012 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
3  * (C) Copyright 2012 Renesas Solutions Corp.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <div64.h>
10 #include <asm/io.h>
11 #include <asm/arch-armv7/globaltimer.h>
12 #include <asm/arch/rmobile.h>
13 
14 static struct globaltimer *global_timer = \
15 		(struct globaltimer *)GLOBAL_TIMER_BASE_ADDR;
16 
17 #define CLK2MHZ(clk)	(clk / 1000 / 1000)
18 static u64 get_cpu_global_timer(void)
19 {
20 	u32 low, high;
21 	u64 timer;
22 
23 	u32 old = readl(&global_timer->cnt_h);
24 	while (1) {
25 		low = readl(&global_timer->cnt_l);
26 		high = readl(&global_timer->cnt_h);
27 		if (old == high)
28 			break;
29 		else
30 			old = high;
31 	}
32 
33 	timer = high;
34 	return (u64)((timer << 32) | low);
35 }
36 
37 static u64 get_time_us(void)
38 {
39 	u64 timer = get_cpu_global_timer();
40 
41 	timer = ((timer << 2) + (CLK2MHZ(CONFIG_SYS_CPU_CLK) >> 1));
42 	do_div(timer, CLK2MHZ(CONFIG_SYS_CPU_CLK));
43 	return timer;
44 }
45 
46 static ulong get_time_ms(void)
47 {
48 	u64 us = get_time_us();
49 
50 	do_div(us, 1000);
51 	return us;
52 }
53 
54 int timer_init(void)
55 {
56 	writel(0x01, &global_timer->ctl);
57 	return 0;
58 }
59 
60 void __udelay(unsigned long usec)
61 {
62 	u64 start, current;
63 	u64 wait;
64 
65 	start = get_cpu_global_timer();
66 	wait = (u64)((usec * CLK2MHZ(CONFIG_SYS_CPU_CLK)) >> 2);
67 	do {
68 		current = get_cpu_global_timer();
69 	} while ((current - start) < wait);
70 }
71 
72 ulong get_timer(ulong base)
73 {
74 	return get_time_ms() - base;
75 }
76 
77 unsigned long long get_ticks(void)
78 {
79 	return get_cpu_global_timer();
80 }
81 
82 ulong get_tbclk(void)
83 {
84 	return (ulong)(CONFIG_SYS_CPU_CLK >> 2);
85 }
86