summaryrefslogtreecommitdiff
path: root/arch/nds32/cpu/n1213/ag102/timer.c
blob: 758b354110ba3948001e72ee1bed2173e255eb67 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 * (C) Copyright 2009 Faraday Technology
 * Po-Yu Chuang <ratbert@faraday-tech.com>
 *
 * Copyright (C) 2011 Andes Technology Corporation
 * Shawn Lin, Andes Technology Corporation <nobuhiro@andestech.com>
 * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <asm/io.h>
#include <faraday/fttmr010.h>

static ulong timestamp;
static ulong lastdec;

int timer_init(void)
{
	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
	unsigned int cr;

	debug("%s()\n", __func__);

	/* disable timers */
	writel(0, &tmr->cr);

#ifdef CONFIG_FTTMR010_EXT_CLK
	/* use 32768Hz oscillator for RTC, WDT, TIMER */
	ftpmu010_32768osc_enable();
#endif

	/* setup timer */
	writel(TIMER_LOAD_VAL, &tmr->timer3_load);
	writel(TIMER_LOAD_VAL, &tmr->timer3_counter);
	writel(0, &tmr->timer3_match1);
	writel(0, &tmr->timer3_match2);

	/* we don't want timer to issue interrupts */
	writel(FTTMR010_TM3_MATCH1 |
	       FTTMR010_TM3_MATCH2 |
	       FTTMR010_TM3_OVERFLOW,
	       &tmr->interrupt_mask);

	cr = readl(&tmr->cr);
#ifdef CONFIG_FTTMR010_EXT_CLK
	cr |= FTTMR010_TM3_CLOCK;	/* use external clock */
#endif
	cr |= FTTMR010_TM3_ENABLE;
	writel(cr, &tmr->cr);

	/* init the timestamp and lastdec value */
	reset_timer_masked();

	return 0;
}

/*
 * timer without interrupts
 */

/*
 * reset time
 */
void reset_timer_masked(void)
{
	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;

	/* capure current decrementer value time */
#ifdef CONFIG_FTTMR010_EXT_CLK
	lastdec = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
#else
	lastdec = readl(&tmr->timer3_counter) /
			(CONFIG_SYS_CLK_FREQ / 2 / CONFIG_SYS_HZ);
#endif
	timestamp = 0;		/* start "advancing" time stamp from 0 */

	debug("%s(): lastdec = %lx\n", __func__, lastdec);
}

void reset_timer(void)
{
	debug("%s()\n", __func__);
	reset_timer_masked();
}

/*
 * return timer ticks
 */
ulong get_timer_masked(void)
{
	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;

	/* current tick value */
#ifdef CONFIG_FTTMR010_EXT_CLK
	ulong now = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
#else
	ulong now = readl(&tmr->timer3_counter) /
			(CONFIG_SYS_CLK_FREQ / 2 / CONFIG_SYS_HZ);
#endif

	debug("%s(): now = %lx, lastdec = %lx\n", __func__, now, lastdec);

	if (lastdec >= now) {
		/*
		 * normal mode (non roll)
		 * move stamp fordward with absoulte diff ticks
		 */
		timestamp += lastdec - now;
	} else {
		/*
		 * we have overflow of the count down timer
		 *
		 * nts = ts + ld + (TLV - now)
		 * ts=old stamp, ld=time that passed before passing through -1
		 * (TLV-now) amount of time after passing though -1
		 * nts = new "advancing time stamp"...it could also roll and
		 * cause problems.
		 */
		timestamp += lastdec + TIMER_LOAD_VAL - now;
	}

	lastdec = now;

	debug("%s() returns %lx\n", __func__, timestamp);

	return timestamp;
}

/*
 * return difference between timer ticks and base
 */
ulong get_timer(ulong base)
{
	debug("%s(%lx)\n", __func__, base);
	return get_timer_masked() - base;
}

void set_timer(ulong t)
{
	debug("%s(%lx)\n", __func__, t);
	timestamp = t;
}

/* delay x useconds AND preserve advance timestamp value */
void __udelay(unsigned long usec)
{
	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;

#ifdef CONFIG_FTTMR010_EXT_CLK
	long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
#else
	long tmo = usec * ((CONFIG_SYS_CLK_FREQ / 2) / 1000) / 1000;
#endif
	unsigned long now, last = readl(&tmr->timer3_counter);

	debug("%s(%lu)\n", __func__, usec);
	while (tmo > 0) {
		now = readl(&tmr->timer3_counter);
		if (now > last) /* count down timer overflow */
			tmo -= TIMER_LOAD_VAL + last - now;
		else
			tmo -= last - now;
		last = now;
	}
}

/*
 * This function is derived from PowerPC code (read timebase as long long).
 * On ARM it just returns the timer value.
 */
unsigned long long get_ticks(void)
{
	debug("%s()\n", __func__);
	return get_timer(0);
}

/*
 * This function is derived from PowerPC code (timebase clock frequency).
 * On ARM it returns the number of timer ticks per second.
 */
ulong get_tbclk(void)
{
	debug("%s()\n", __func__);
#ifdef CONFIG_FTTMR010_EXT_CLK
	return CONFIG_SYS_HZ;
#else
	return CONFIG_SYS_CLK_FREQ;
#endif
}