xref: /OK3568_Linux_fs/u-boot/arch/arm/cpu/armv7/ls102xa/timer.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright 2014 Freescale Semiconductor, Inc.
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:     GPL-2.0+
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <asm/io.h>
9*4882a593Smuzhiyun #include <div64.h>
10*4882a593Smuzhiyun #include <asm/arch/immap_ls102xa.h>
11*4882a593Smuzhiyun #include <asm/arch/clock.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun /*
16*4882a593Smuzhiyun  * This function is intended for SHORT delays only.
17*4882a593Smuzhiyun  * It will overflow at around 10 seconds @ 400MHz,
18*4882a593Smuzhiyun  * or 20 seconds @ 200MHz.
19*4882a593Smuzhiyun  */
usec2ticks(unsigned long usec)20*4882a593Smuzhiyun unsigned long usec2ticks(unsigned long usec)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun 	ulong ticks;
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun 	if (usec < 1000)
25*4882a593Smuzhiyun 		ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
26*4882a593Smuzhiyun 	else
27*4882a593Smuzhiyun 		ticks = ((usec / 10) * (get_tbclk() / 100000));
28*4882a593Smuzhiyun 
29*4882a593Smuzhiyun 	return ticks;
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun 
tick_to_time(unsigned long long tick)32*4882a593Smuzhiyun static inline unsigned long long tick_to_time(unsigned long long tick)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun 	unsigned long freq;
35*4882a593Smuzhiyun 
36*4882a593Smuzhiyun 	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun 	tick *= CONFIG_SYS_HZ;
39*4882a593Smuzhiyun 	do_div(tick, freq);
40*4882a593Smuzhiyun 
41*4882a593Smuzhiyun 	return tick;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun 
us_to_tick(unsigned long long usec)44*4882a593Smuzhiyun static inline unsigned long long us_to_tick(unsigned long long usec)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun 	unsigned long freq;
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun 	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun 	usec = usec * freq  + 999999;
51*4882a593Smuzhiyun 	do_div(usec, 1000000);
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun 	return usec;
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun 
timer_init(void)56*4882a593Smuzhiyun int timer_init(void)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun 	struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
59*4882a593Smuzhiyun 	unsigned long ctrl, freq;
60*4882a593Smuzhiyun 	unsigned long long val;
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun 	/* Enable System Counter */
63*4882a593Smuzhiyun 	writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr);
64*4882a593Smuzhiyun 
65*4882a593Smuzhiyun 	freq = COUNTER_FREQUENCY;
66*4882a593Smuzhiyun 	asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun 	/* Set PL1 Physical Timer Ctrl */
69*4882a593Smuzhiyun 	ctrl = ARCH_TIMER_CTRL_ENABLE;
70*4882a593Smuzhiyun 	asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl));
71*4882a593Smuzhiyun 
72*4882a593Smuzhiyun 	/* Set PL1 Physical Comp Value */
73*4882a593Smuzhiyun 	val = TIMER_COMP_VAL;
74*4882a593Smuzhiyun 	asm("mcrr p15, 2, %Q0, %R0, c14" : : "r" (val));
75*4882a593Smuzhiyun 
76*4882a593Smuzhiyun 	gd->arch.tbl = 0;
77*4882a593Smuzhiyun 	gd->arch.tbu = 0;
78*4882a593Smuzhiyun 
79*4882a593Smuzhiyun 	return 0;
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun 
get_ticks(void)82*4882a593Smuzhiyun unsigned long long get_ticks(void)
83*4882a593Smuzhiyun {
84*4882a593Smuzhiyun 	unsigned long long now;
85*4882a593Smuzhiyun 
86*4882a593Smuzhiyun 	asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun 	gd->arch.tbl = (unsigned long)(now & 0xffffffff);
89*4882a593Smuzhiyun 	gd->arch.tbu = (unsigned long)(now >> 32);
90*4882a593Smuzhiyun 
91*4882a593Smuzhiyun 	return now;
92*4882a593Smuzhiyun }
93*4882a593Smuzhiyun 
get_timer_masked(void)94*4882a593Smuzhiyun unsigned long get_timer_masked(void)
95*4882a593Smuzhiyun {
96*4882a593Smuzhiyun 	return tick_to_time(get_ticks());
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun 
get_timer(ulong base)99*4882a593Smuzhiyun unsigned long get_timer(ulong base)
100*4882a593Smuzhiyun {
101*4882a593Smuzhiyun 	return get_timer_masked() - base;
102*4882a593Smuzhiyun }
103*4882a593Smuzhiyun 
104*4882a593Smuzhiyun /* delay x useconds and preserve advance timstamp value */
__udelay(unsigned long usec)105*4882a593Smuzhiyun void __udelay(unsigned long usec)
106*4882a593Smuzhiyun {
107*4882a593Smuzhiyun 	unsigned long long start;
108*4882a593Smuzhiyun 	unsigned long tmo;
109*4882a593Smuzhiyun 
110*4882a593Smuzhiyun 	start = get_ticks();			/* get current timestamp */
111*4882a593Smuzhiyun 	tmo = us_to_tick(usec);			/* convert usecs to ticks */
112*4882a593Smuzhiyun 
113*4882a593Smuzhiyun 	while ((get_ticks() - start) < tmo)
114*4882a593Smuzhiyun 		;				/* loop till time has passed */
115*4882a593Smuzhiyun }
116*4882a593Smuzhiyun 
117*4882a593Smuzhiyun /*
118*4882a593Smuzhiyun  * This function is derived from PowerPC code (timebase clock frequency).
119*4882a593Smuzhiyun  * On ARM it returns the number of timer ticks per second.
120*4882a593Smuzhiyun  */
get_tbclk(void)121*4882a593Smuzhiyun unsigned long get_tbclk(void)
122*4882a593Smuzhiyun {
123*4882a593Smuzhiyun 	unsigned long freq;
124*4882a593Smuzhiyun 
125*4882a593Smuzhiyun 	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
126*4882a593Smuzhiyun 
127*4882a593Smuzhiyun 	return freq;
128*4882a593Smuzhiyun }
129