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 
22 static vu_long cmt0_timer;
23 
cmt_timer_start(unsigned int timer)24 static void cmt_timer_start(unsigned int timer)
25 {
26 	writew(readw(CMSTR) | 0x01, CMSTR);
27 }
28 
cmt_timer_stop(unsigned int timer)29 static void cmt_timer_stop(unsigned int timer)
30 {
31 	writew(readw(CMSTR) & ~0x01, CMSTR);
32 }
33 
timer_init(void)34 int 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 
get_ticks(void)49 unsigned long long get_ticks(void)
50 {
51 	return cmt0_timer;
52 }
53 
54 static vu_long cmcnt = 0;
get_usec(void)55 static 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 */
get_timer(ulong base)74 ulong get_timer(ulong base)
75 {
76 	return (get_usec() / 1000) - base;
77 }
78 
__udelay(unsigned long usec)79 void __udelay(unsigned long usec)
80 {
81 	unsigned long end = get_usec() + usec;
82 
83 	while (get_usec() < end)
84 		continue;
85 }
86 
get_tbclk(void)87 unsigned long get_tbclk(void)
88 {
89 	return CONFIG_SH_CMT_CLK_FREQ;
90 }
91