1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
4 * Copyright (C) 2008 Renesas Solutions Corp.
5 *
6 * (C) Copyright 2003
7 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
8 */
9
10#include <common.h>
11#include <init.h>
12#include <time.h>
13#include <asm/io.h>
14#include <asm/processor.h>
15#include <linux/delay.h>
16
17#define CMT_CMCSR_INIT	0x0001	/* PCLK/32 */
18#define CMT_CMCSR_CALIB 0x0000
19#define CMT_MAX_COUNTER (0xFFFFFFFF)
20#define CMT_TIMER_RESET (0xFFFF)
21
22static vu_long cmt0_timer;
23
24static void cmt_timer_start(unsigned int timer)
25{
26	writew(readw(CMSTR) | 0x01, CMSTR);
27}
28
29static void cmt_timer_stop(unsigned int timer)
30{
31	writew(readw(CMSTR) & ~0x01, CMSTR);
32}
33
34int timer_init(void)
35{
36	cmt0_timer = 0;
37	/* Divide clock by 32 */
38	readw(CMCSR_0);
39	writew(CMT_CMCSR_INIT, CMCSR_0);
40
41	/* User Device 0 only */
42	cmt_timer_stop(0);
43	writew(CMT_TIMER_RESET, CMCOR_0);
44	cmt_timer_start(0);
45
46	return 0;
47}
48
49unsigned long long get_ticks(void)
50{
51	return cmt0_timer;
52}
53
54static vu_long cmcnt = 0;
55static unsigned long get_usec (void)
56{
57	ulong data = readw(CMCNT_0);
58
59	if (data >= cmcnt)
60		cmcnt = data - cmcnt;
61	else
62		cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
63
64	if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
65		cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
66	else
67		cmt0_timer += cmcnt;
68
69	cmcnt = data;
70	return cmt0_timer;
71}
72
73/* return msec */
74ulong get_timer(ulong base)
75{
76	return (get_usec() / 1000) - base;
77}
78
79void __udelay(unsigned long usec)
80{
81	unsigned long end = get_usec() + usec;
82
83	while (get_usec() < end)
84		continue;
85}
86
87unsigned long get_tbclk(void)
88{
89	return CONFIG_SH_CMT_CLK_FREQ;
90}
91