xref: /openbmc/u-boot/arch/sh/lib/time.c (revision 425faf74)
1 /*
2  * (C) Copyright 2009
3  * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
4  *
5  * (C) Copyright 2007-2012
6  * Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
7  *
8  * (C) Copyright 2003
9  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
10  *
11  * SPDX-License-Identifier:	GPL-2.0+
12  */
13 
14 #include <common.h>
15 #include <div64.h>
16 #include <asm/processor.h>
17 #include <asm/io.h>
18 #include <sh_tmu.h>
19 
20 static struct tmu_regs *tmu = (struct tmu_regs *)TMU_BASE;
21 
22 static u16 bit;
23 static unsigned long last_tcnt;
24 static unsigned long long overflow_ticks;
25 
26 unsigned long get_tbclk(void)
27 {
28 	return get_tmu0_clk_rate() >> ((bit + 1) * 2);
29 }
30 
31 static inline unsigned long long tick_to_time(unsigned long long tick)
32 {
33 	tick *= CONFIG_SYS_HZ;
34 	do_div(tick, get_tbclk());
35 
36 	return tick;
37 }
38 
39 static inline unsigned long long usec_to_tick(unsigned long long usec)
40 {
41 	usec *= get_tbclk();
42 	do_div(usec, 1000000);
43 
44 	return usec;
45 }
46 
47 static void tmu_timer_start(unsigned int timer)
48 {
49 	if (timer > 2)
50 		return;
51 	writeb(readb(&tmu->tstr) | (1 << timer), &tmu->tstr);
52 }
53 
54 static void tmu_timer_stop(unsigned int timer)
55 {
56 	if (timer > 2)
57 		return;
58 	writeb(readb(&tmu->tstr) & ~(1 << timer), &tmu->tstr);
59 }
60 
61 int timer_init(void)
62 {
63 	bit = (ffs(CONFIG_SYS_TMU_CLK_DIV) >> 1) - 1;
64 	writew(readw(&tmu->tcr0) | bit, &tmu->tcr0);
65 
66 	tmu_timer_stop(0);
67 	tmu_timer_start(0);
68 
69 	last_tcnt = 0;
70 	overflow_ticks = 0;
71 
72 	return 0;
73 }
74 
75 unsigned long long get_ticks(void)
76 {
77 	unsigned long tcnt = 0 - readl(&tmu->tcnt0);
78 
79 	if (last_tcnt > tcnt) /* overflow */
80 		overflow_ticks++;
81 	last_tcnt = tcnt;
82 
83 	return (overflow_ticks << 32) | tcnt;
84 }
85 
86 void __udelay(unsigned long usec)
87 {
88 	unsigned long long tmp;
89 	ulong tmo;
90 
91 	tmo = usec_to_tick(usec);
92 	tmp = get_ticks() + tmo;	/* get current timestamp */
93 
94 	while (get_ticks() < tmp)	/* loop till event */
95 		 /*NOP*/;
96 }
97 
98 unsigned long get_timer(unsigned long base)
99 {
100 	/* return msec */
101 	return tick_to_time(get_ticks()) - base;
102 }
103 
104 void set_timer(unsigned long t)
105 {
106 	writel((0 - t), &tmu->tcnt0);
107 }
108 
109 void reset_timer(void)
110 {
111 	tmu_timer_stop(0);
112 	set_timer(0);
113 	tmu_timer_start(0);
114 }
115