aboutsummaryrefslogtreecommitdiff
path: root/arch/m68knommu/platform/5307/timers.c
blob: c3a9755c2d1f2e6398d07dd849eb1909761d53fa (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
/***************************************************************************/

/*
 *	timers.c -- generic ColdFire hardware timer support.
 *
 *	Copyright (C) 1999-2003, Greg Ungerer (gerg@snapgear.com)
 */

/***************************************************************************/

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/param.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/machdep.h>
#include <asm/coldfire.h>
#include <asm/mcftimer.h>
#include <asm/mcfsim.h>

/***************************************************************************/

/*
 *	By default use timer1 as the system clock timer.
 */
#define	TA(a)	(MCF_MBAR + MCFTIMER_BASE1 + (a))

/*
 *	Default the timer and vector to use for ColdFire. Some ColdFire
 *	CPU's and some boards may want different. Their sub-architecture
 *	startup code (in config.c) can change these if they want.
 */
unsigned int	mcf_timervector = 29;
unsigned int	mcf_profilevector = 31;
unsigned int	mcf_timerlevel = 5;

/*
 *	These provide the underlying interrupt vector support.
 *	Unfortunately it is a little different on each ColdFire.
 */
extern void mcf_settimericr(int timer, int level);
extern int mcf_timerirqpending(int timer);

/***************************************************************************/

void coldfire_tick(void)
{
	/* Reset the ColdFire timer */
	__raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER));
}

/***************************************************************************/

void coldfire_timer_init(irqreturn_t (*handler)(int, void *, struct pt_regs *))
{
	__raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));
	__raw_writew(((MCF_BUSCLK / 16) / HZ), TA(MCFTIMER_TRR));
	__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
		MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));

	request_irq(mcf_timervector, handler, SA_INTERRUPT, "timer", NULL);
	mcf_settimericr(1, mcf_timerlevel);

#ifdef CONFIG_HIGHPROFILE
	coldfire_profile_init();
#endif
}

/***************************************************************************/

unsigned long coldfire_timer_offset(void)
{
	unsigned long trr, tcn, offset;

	tcn = __raw_readw(TA(MCFTIMER_TCN));
	trr = __raw_readw(TA(MCFTIMER_TRR));
	offset = (tcn * (1000000 / HZ)) / trr;

	/* Check if we just wrapped the counters and maybe missed a tick */
	if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1))
		offset += 1000000 / HZ;
	return offset;
}

/***************************************************************************/
#ifdef CONFIG_HIGHPROFILE
/***************************************************************************/

/*
 *	By default use timer2 as the profiler clock timer.
 */
#define	PA(a)	(MCF_MBAR + MCFTIMER_BASE2 + (a))

/*
 *	Choose a reasonably fast profile timer. Make it an odd value to
 *	try and get good coverage of kernal operations.
 */
#define	PROFILEHZ	1013

/*
 *	Use the other timer to provide high accuracy profiling info.
 */
void coldfire_profile_tick(int irq, void *dummy, struct pt_regs *regs)
{
	/* Reset ColdFire timer2 */
	__raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, PA(MCFTIMER_TER));
	if (current->pid)
		profile_tick(CPU_PROFILING, regs);
}

/***************************************************************************/

void coldfire_profile_init(void)
{
	printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n", PROFILEHZ);

	/* Set up TIMER 2 as high speed profile clock */
	__raw_writew(MCFTIMER_TMR_DISABLE, PA(MCFTIMER_TMR));

	__raw_writew(((MCF_CLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR));
	__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
		MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR));

	request_irq(mcf_profilevector, coldfire_profile_tick,
		(SA_INTERRUPT | IRQ_FLG_FAST), "profile timer", NULL);
	mcf_settimericr(2, 7);
}

/***************************************************************************/
#endif	/* CONFIG_HIGHPROFILE */
/***************************************************************************/