xref: /OK3568_Linux_fs/u-boot/arch/sh/lib/time_sh2.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
3*4882a593Smuzhiyun  * Copyright (C) 2008 Renesas Solutions Corp.
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * (C) Copyright 2003
6*4882a593Smuzhiyun  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
7*4882a593Smuzhiyun  *
8*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
9*4882a593Smuzhiyun  */
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #include <common.h>
12*4882a593Smuzhiyun #include <asm/io.h>
13*4882a593Smuzhiyun #include <asm/processor.h>
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #define CMT_CMCSR_INIT	0x0001	/* PCLK/32 */
16*4882a593Smuzhiyun #define CMT_CMCSR_CALIB 0x0000
17*4882a593Smuzhiyun #define CMT_MAX_COUNTER (0xFFFFFFFF)
18*4882a593Smuzhiyun #define CMT_TIMER_RESET (0xFFFF)
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun static vu_long cmt0_timer;
21*4882a593Smuzhiyun 
cmt_timer_start(unsigned int timer)22*4882a593Smuzhiyun static void cmt_timer_start(unsigned int timer)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun 	writew(readw(CMSTR) | 0x01, CMSTR);
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun 
cmt_timer_stop(unsigned int timer)27*4882a593Smuzhiyun static void cmt_timer_stop(unsigned int timer)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun 	writew(readw(CMSTR) & ~0x01, CMSTR);
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun 
timer_init(void)32*4882a593Smuzhiyun int timer_init(void)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun 	cmt0_timer = 0;
35*4882a593Smuzhiyun 	/* Divide clock by 32 */
36*4882a593Smuzhiyun 	readw(CMCSR_0);
37*4882a593Smuzhiyun 	writew(CMT_CMCSR_INIT, CMCSR_0);
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun 	/* User Device 0 only */
40*4882a593Smuzhiyun 	cmt_timer_stop(0);
41*4882a593Smuzhiyun 	writew(CMT_TIMER_RESET, CMCOR_0);
42*4882a593Smuzhiyun 	cmt_timer_start(0);
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun 	return 0;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun 
get_ticks(void)47*4882a593Smuzhiyun unsigned long long get_ticks(void)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun 	return cmt0_timer;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun static vu_long cmcnt = 0;
get_usec(void)53*4882a593Smuzhiyun static unsigned long get_usec (void)
54*4882a593Smuzhiyun {
55*4882a593Smuzhiyun 	ulong data = readw(CMCNT_0);
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun 	if (data >= cmcnt)
58*4882a593Smuzhiyun 		cmcnt = data - cmcnt;
59*4882a593Smuzhiyun 	else
60*4882a593Smuzhiyun 		cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun 	if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
63*4882a593Smuzhiyun 		cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
64*4882a593Smuzhiyun 	else
65*4882a593Smuzhiyun 		cmt0_timer += cmcnt;
66*4882a593Smuzhiyun 
67*4882a593Smuzhiyun 	cmcnt = data;
68*4882a593Smuzhiyun 	return cmt0_timer;
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun 
71*4882a593Smuzhiyun /* return msec */
get_timer(ulong base)72*4882a593Smuzhiyun ulong get_timer(ulong base)
73*4882a593Smuzhiyun {
74*4882a593Smuzhiyun 	return (get_usec() / 1000) - base;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun 
__udelay(unsigned long usec)77*4882a593Smuzhiyun void __udelay(unsigned long usec)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun 	unsigned long end = get_usec() + usec;
80*4882a593Smuzhiyun 
81*4882a593Smuzhiyun 	while (get_usec() < end)
82*4882a593Smuzhiyun 		continue;
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun 
get_tbclk(void)85*4882a593Smuzhiyun unsigned long get_tbclk(void)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun 	return CONFIG_SH_CMT_CLK_FREQ;
88*4882a593Smuzhiyun }
89