summaryrefslogtreecommitdiff
path: root/arch/arm/cpu/arm926ejs/armada100/timer.c
blob: d2ecbd07e2fb58b0a50680c76ee99971550286c8 (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
192
193
// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2010
 * Marvell Semiconductor <www.marvell.com>
 * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
 * Contributor: Mahavir Jain <mjain@marvell.com>
 */

#include <common.h>
#include <asm/arch/cpu.h>
#include <asm/arch/armada100.h>

/*
 * Timer registers
 * Refer Section A.6 in Datasheet
 */
struct armd1tmr_registers {
	u32 clk_ctrl;	/* Timer clk control reg */
	u32 match[9];	/* Timer match registers */
	u32 count[3];	/* Timer count registers */
	u32 status[3];
	u32 ie[3];
	u32 preload[3];	/* Timer preload value */
	u32 preload_ctrl[3];
	u32 wdt_match_en;
	u32 wdt_match_r;
	u32 wdt_val;
	u32 wdt_sts;
	u32 icr[3];
	u32 wdt_icr;
	u32 cer;	/* Timer count enable reg */
	u32 cmr;
	u32 ilr[3];
	u32 wcr;
	u32 wfar;
	u32 wsar;
	u32 cvwr;
};

#define TIMER			0	/* Use TIMER 0 */
/* Each timer has 3 match registers */
#define MATCH_CMP(x)		((3 * TIMER) + x)
#define TIMER_LOAD_VAL 		0xffffffff
#define	COUNT_RD_REQ		0x1

DECLARE_GLOBAL_DATA_PTR;
/* Using gd->arch.tbu from timestamp and gd->arch.tbl for lastdec */

/* For preventing risk of instability in reading counter value,
 * first set read request to register cvwr and then read same
 * register after it captures counter value.
 */
ulong read_timer(void)
{
	struct armd1tmr_registers *armd1timers =
		(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
	volatile int loop=100;

	writel(COUNT_RD_REQ, &armd1timers->cvwr);
	while (loop--);
	return(readl(&armd1timers->cvwr));
}

static ulong get_timer_masked(void)
{
	ulong now = read_timer();

	if (now >= gd->arch.tbl) {
		/* normal mode */
		gd->arch.tbu += now - gd->arch.tbl;
	} else {
		/* we have an overflow ... */
		gd->arch.tbu += now + TIMER_LOAD_VAL - gd->arch.tbl;
	}
	gd->arch.tbl = now;

	return gd->arch.tbu;
}

ulong get_timer(ulong base)
{
	return ((get_timer_masked() / (CONFIG_SYS_HZ_CLOCK / 1000)) -
		base);
}

void __udelay(unsigned long usec)
{
	ulong delayticks;
	ulong endtime;

	delayticks = (usec * (CONFIG_SYS_HZ_CLOCK / 1000000));
	endtime = get_timer_masked() + delayticks;

	while (get_timer_masked() < endtime);
}

/*
 * init the Timer
 */
int timer_init(void)
{
	struct armd1apb1_registers *apb1clkres =
		(struct armd1apb1_registers *) ARMD1_APBC1_BASE;
	struct armd1tmr_registers *armd1timers =
		(struct armd1tmr_registers *) ARMD1_TIMER_BASE;

	/* Enable Timer clock at 3.25 MHZ */
	writel(APBC_APBCLK | APBC_FNCLK | APBC_FNCLKSEL(3), &apb1clkres->timers);

	/* load value into timer */
	writel(0x0, &armd1timers->clk_ctrl);
	/* Use Timer 0 Match Resiger 0 */
	writel(TIMER_LOAD_VAL, &armd1timers->match[MATCH_CMP(0)]);
	/* Preload value is 0 */
	writel(0x0, &armd1timers->preload[TIMER]);
	/* Enable match comparator 0 for Timer 0 */
	writel(0x1, &armd1timers->preload_ctrl[TIMER]);

	/* Enable timer 0 */
	writel(0x1, &armd1timers->cer);
	/* init the gd->arch.tbu and gd->arch.tbl value */
	gd->arch.tbl = read_timer();
	gd->arch.tbu = 0;

	return 0;
}

#define MPMU_APRR_WDTR	(1<<4)
#define TMR_WFAR	0xbaba	/* WDT Register First key */
#define TMP_WSAR	0xeb10	/* WDT Register Second key */

/*
 * This function uses internal Watchdog Timer
 * based reset mechanism.
 * Steps to write watchdog registers (protected access)
 * 1. Write key value to TMR_WFAR reg.
 * 2. Write key value to TMP_WSAR reg.
 * 3. Perform write operation.
 */
void reset_cpu (unsigned long ignored)
{
	struct armd1mpmu_registers *mpmu =
		(struct armd1mpmu_registers *) ARMD1_MPMU_BASE;
	struct armd1tmr_registers *armd1timers =
		(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
	u32 val;

	/* negate hardware reset to the WDT after system reset */
	val = readl(&mpmu->aprr);
	val = val | MPMU_APRR_WDTR;
	writel(val, &mpmu->aprr);

	/* reset/enable WDT clock */
	writel(APBC_APBCLK | APBC_FNCLK | APBC_RST, &mpmu->wdtpcr);
	readl(&mpmu->wdtpcr);
	writel(APBC_APBCLK | APBC_FNCLK, &mpmu->wdtpcr);
	readl(&mpmu->wdtpcr);

	/* clear previous WDT status */
	writel(TMR_WFAR, &armd1timers->wfar);
	writel(TMP_WSAR, &armd1timers->wsar);
	writel(0, &armd1timers->wdt_sts);

	/* set match counter */
	writel(TMR_WFAR, &armd1timers->wfar);
	writel(TMP_WSAR, &armd1timers->wsar);
	writel(0xf, &armd1timers->wdt_match_r);

	/* enable WDT reset */
	writel(TMR_WFAR, &armd1timers->wfar);
	writel(TMP_WSAR, &armd1timers->wsar);
	writel(0x3, &armd1timers->wdt_match_en);

	while(1);
}

/*
 * 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)
{
	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)
{
	return (ulong)CONFIG_SYS_HZ;
}