xref: /openbmc/u-boot/arch/sh/lib/time.c (revision 5c8d14df)
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  * See file CREDITS for list of people who contributed to this
12  * project.
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU General Public License as
16  * published by the Free Software Foundation; either version 2 of
17  * the License, or (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with this program; if not, write to the Free Software
26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27  * MA 02111-1307 USA
28  */
29 
30 #include <common.h>
31 #include <div64.h>
32 #include <asm/processor.h>
33 #include <asm/io.h>
34 #include <sh_tmu.h>
35 
36 static struct tmu_regs *tmu = (struct tmu_regs *)TMU_BASE;
37 
38 static u16 bit;
39 static unsigned long last_tcnt;
40 static unsigned long long overflow_ticks;
41 
42 unsigned long get_tbclk(void)
43 {
44 	return get_tmu0_clk_rate() >> ((bit + 1) * 2);
45 }
46 
47 static inline unsigned long long tick_to_time(unsigned long long tick)
48 {
49 	tick *= CONFIG_SYS_HZ;
50 	do_div(tick, get_tbclk());
51 
52 	return tick;
53 }
54 
55 static inline unsigned long long usec_to_tick(unsigned long long usec)
56 {
57 	usec *= get_tbclk();
58 	do_div(usec, 1000000);
59 
60 	return usec;
61 }
62 
63 static void tmu_timer_start(unsigned int timer)
64 {
65 	if (timer > 2)
66 		return;
67 	writeb(readb(&tmu->tstr) | (1 << timer), &tmu->tstr);
68 }
69 
70 static void tmu_timer_stop(unsigned int timer)
71 {
72 	if (timer > 2)
73 		return;
74 	writeb(readb(&tmu->tstr) & ~(1 << timer), &tmu->tstr);
75 }
76 
77 int timer_init(void)
78 {
79 	bit = (ffs(CONFIG_SYS_TMU_CLK_DIV) >> 1) - 1;
80 	writew(readw(&tmu->tcr0) | bit, &tmu->tcr0);
81 
82 	tmu_timer_stop(0);
83 	tmu_timer_start(0);
84 
85 	last_tcnt = 0;
86 	overflow_ticks = 0;
87 
88 	return 0;
89 }
90 
91 unsigned long long get_ticks(void)
92 {
93 	unsigned long tcnt = 0 - readl(&tmu->tcnt0);
94 
95 	if (last_tcnt > tcnt) /* overflow */
96 		overflow_ticks++;
97 	last_tcnt = tcnt;
98 
99 	return (overflow_ticks << 32) | tcnt;
100 }
101 
102 void __udelay(unsigned long usec)
103 {
104 	unsigned long long tmp;
105 	ulong tmo;
106 
107 	tmo = usec_to_tick(usec);
108 	tmp = get_ticks() + tmo;	/* get current timestamp */
109 
110 	while (get_ticks() < tmp)	/* loop till event */
111 		 /*NOP*/;
112 }
113 
114 unsigned long get_timer(unsigned long base)
115 {
116 	/* return msec */
117 	return tick_to_time(get_ticks()) - base;
118 }
119 
120 void set_timer(unsigned long t)
121 {
122 	writel((0 - t), &tmu->tcnt0);
123 }
124 
125 void reset_timer(void)
126 {
127 	tmu_timer_stop(0);
128 	set_timer(0);
129 	tmu_timer_start(0);
130 }
131