xref: /OK3568_Linux_fs/u-boot/arch/arm/cpu/armv8/generic_timer.c (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * (C) Copyright 2013
3*4882a593Smuzhiyun  * David Feng <fenghua@phytium.com.cn>
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
6*4882a593Smuzhiyun  */
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #include <common.h>
9*4882a593Smuzhiyun #include <command.h>
10*4882a593Smuzhiyun #include <asm/system.h>
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun /*
15*4882a593Smuzhiyun  * Generic timer implementation of get_tbclk()
16*4882a593Smuzhiyun  */
get_tbclk(void)17*4882a593Smuzhiyun unsigned long get_tbclk(void)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun 	unsigned long cntfrq;
20*4882a593Smuzhiyun 	asm volatile("mrs %0, cntfrq_el0" : "=r" (cntfrq));
21*4882a593Smuzhiyun 	return cntfrq;
22*4882a593Smuzhiyun }
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun /*
25*4882a593Smuzhiyun  * Generic timer implementation of timer_read_counter()
26*4882a593Smuzhiyun  */
timer_read_counter(void)27*4882a593Smuzhiyun unsigned long timer_read_counter(void)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun 	unsigned long cntpct;
30*4882a593Smuzhiyun #ifdef CONFIG_SYS_FSL_ERRATUM_A008585
31*4882a593Smuzhiyun 	/* This erratum number needs to be confirmed to match ARM document */
32*4882a593Smuzhiyun 	unsigned long temp;
33*4882a593Smuzhiyun #endif
34*4882a593Smuzhiyun 	isb();
35*4882a593Smuzhiyun 	asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct));
36*4882a593Smuzhiyun #ifdef CONFIG_SYS_FSL_ERRATUM_A008585
37*4882a593Smuzhiyun 	asm volatile("mrs %0, cntpct_el0" : "=r" (temp));
38*4882a593Smuzhiyun 	while (temp != cntpct) {
39*4882a593Smuzhiyun 		asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct));
40*4882a593Smuzhiyun 		asm volatile("mrs %0, cntpct_el0" : "=r" (temp));
41*4882a593Smuzhiyun 	}
42*4882a593Smuzhiyun #endif
43*4882a593Smuzhiyun 	return cntpct;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun 
get_ticks(void)46*4882a593Smuzhiyun uint64_t get_ticks(void)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun 	unsigned long ticks = timer_read_counter();
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun 	gd->arch.tbl = ticks;
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun 	return ticks;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun 
usec2ticks(unsigned long usec)55*4882a593Smuzhiyun unsigned long usec2ticks(unsigned long usec)
56*4882a593Smuzhiyun {
57*4882a593Smuzhiyun 	ulong ticks;
58*4882a593Smuzhiyun 	if (usec < 1000)
59*4882a593Smuzhiyun 		ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
60*4882a593Smuzhiyun 	else
61*4882a593Smuzhiyun 		ticks = ((usec / 10) * (get_tbclk() / 100000));
62*4882a593Smuzhiyun 
63*4882a593Smuzhiyun 	return ticks;
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun 
timer_get_boot_us(void)66*4882a593Smuzhiyun ulong timer_get_boot_us(void)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun 	ulong count = timer_read_counter();
69*4882a593Smuzhiyun 
70*4882a593Smuzhiyun 	return count/24;
71*4882a593Smuzhiyun }
72