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