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
|
/*
* arch/arm/mach-iop3xx/iop321-time.c
*
* Timer code for IOP321 based systems
*
* Author: Deepak Saxena <dsaxena@mvista.com>
*
* Copyright 2002-2003 MontaVista Software Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/timex.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/mach-types.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#define IOP321_TIME_SYNC 0
static inline unsigned long get_elapsed(void)
{
return LATCH - *IOP321_TU_TCR0;
}
static unsigned long iop321_gettimeoffset(void)
{
unsigned long elapsed, usec;
u32 tisr1, tisr2;
/*
* If an interrupt was pending before we read the timer,
* we've already wrapped. Factor this into the time.
* If an interrupt was pending after we read the timer,
* it may have wrapped between checking the interrupt
* status and reading the timer. Re-read the timer to
* be sure its value is after the wrap.
*/
asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr1));
elapsed = get_elapsed();
asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr2));
if(tisr1 & 1)
elapsed += LATCH;
else if (tisr2 & 1)
elapsed = LATCH + get_elapsed();
/*
* Now convert them to usec.
*/
usec = (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH;
return usec;
}
static irqreturn_t
iop321_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
u32 tisr;
write_seqlock(&xtime_lock);
asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr));
tisr |= 1;
asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (tisr));
timer_tick(regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction iop321_timer_irq = {
.name = "IOP321 Timer Tick",
.handler = iop321_timer_interrupt,
.flags = SA_INTERRUPT
};
static void __init iop321_timer_init(void)
{
u32 timer_ctl;
setup_irq(IRQ_IOP321_TIMER0, &iop321_timer_irq);
timer_ctl = IOP321_TMR_EN | IOP321_TMR_PRIVILEGED | IOP321_TMR_RELOAD |
IOP321_TMR_RATIO_1_1;
asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (LATCH));
asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (timer_ctl));
}
struct sys_timer iop321_timer = {
.init = &iop321_timer_init,
.offset = iop321_gettimeoffset,
};
|
