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
|
/*
* arch/blackfin/kernel/time.c
*
* This file contains the Blackfin-specific time handling details.
* Most of the stuff is located in the machine specific files.
*
* Copyright 2004-2008 Analog Devices Inc.
* Licensed under the GPL-2 or later.
*/
#include <linux/module.h>
#include <linux/profile.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <asm/blackfin.h>
#include <asm/time.h>
#include <asm/gptimers.h>
/* This is an NTP setting */
#define TICK_SIZE (tick_nsec / 1000)
static struct irqaction bfin_timer_irq = {
.name = "Blackfin Timer Tick",
};
#if defined(CONFIG_IPIPE)
void __init setup_system_timer0(void)
{
/* Power down the core timer, just to play safe. */
bfin_write_TCNTL(0);
disable_gptimers(TIMER0bit);
set_gptimer_status(0, TIMER_STATUS_TRUN0);
while (get_gptimer_status(0) & TIMER_STATUS_TRUN0)
udelay(10);
set_gptimer_config(0, 0x59); /* IRQ enable, periodic, PWM_OUT, SCLKed, OUT PAD disabled */
set_gptimer_period(TIMER0_id, get_sclk() / HZ);
set_gptimer_pwidth(TIMER0_id, 1);
SSYNC();
enable_gptimers(TIMER0bit);
}
#else
void __init setup_core_timer(void)
{
u32 tcount;
/* power up the timer, but don't enable it just yet */
bfin_write_TCNTL(TMPWR);
CSYNC();
/* the TSCALE prescaler counter */
bfin_write_TSCALE(TIME_SCALE - 1);
tcount = ((get_cclk() / (HZ * TIME_SCALE)) - 1);
bfin_write_TPERIOD(tcount);
bfin_write_TCOUNT(tcount);
/* now enable the timer */
CSYNC();
bfin_write_TCNTL(TAUTORLD | TMREN | TMPWR);
}
#endif
static void __init
time_sched_init(irqreturn_t(*timer_routine) (int, void *))
{
#if defined(CONFIG_IPIPE)
setup_system_timer0();
bfin_timer_irq.handler = timer_routine;
setup_irq(IRQ_TIMER0, &bfin_timer_irq);
#else
setup_core_timer();
bfin_timer_irq.handler = timer_routine;
setup_irq(IRQ_CORETMR, &bfin_timer_irq);
#endif
}
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
/*
* Should return useconds since last timer tick
*/
u32 arch_gettimeoffset(void)
{
unsigned long offset;
unsigned long clocks_per_jiffy;
#if defined(CONFIG_IPIPE)
clocks_per_jiffy = bfin_read_TIMER0_PERIOD();
offset = bfin_read_TIMER0_COUNTER() / \
(((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
if ((get_gptimer_status(0) & TIMER_STATUS_TIMIL0) && offset < (100000 / HZ / 2))
offset += (USEC_PER_SEC / HZ);
#else
clocks_per_jiffy = bfin_read_TPERIOD();
offset = (clocks_per_jiffy - bfin_read_TCOUNT()) / \
(((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
/* Check if we just wrapped the counters and maybe missed a tick */
if ((bfin_read_ILAT() & (1 << IRQ_CORETMR))
&& (offset < (100000 / HZ / 2)))
offset += (USEC_PER_SEC / HZ);
#endif
return offset;
}
#endif
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "xtime_update()" routine every clocktick
*/
#ifdef CONFIG_CORE_TIMER_IRQ_L1
__attribute__((l1_text))
#endif
irqreturn_t timer_interrupt(int irq, void *dummy)
{
xtime_update(1);
#ifdef CONFIG_IPIPE
update_root_process_times(get_irq_regs());
#else
update_process_times(user_mode(get_irq_regs()));
#endif
profile_tick(CPU_PROFILING);
return IRQ_HANDLED;
}
void read_persistent_clock(struct timespec *ts)
{
time_t secs_since_1970 = (365 * 37 + 9) * 24 * 60 * 60; /* 1 Jan 2007 */
ts->tv_sec = secs_since_1970;
ts->tv_nsec = 0;
}
void __init time_init(void)
{
#ifdef CONFIG_RTC_DRV_BFIN
/* [#2663] hack to filter junk RTC values that would cause
* userspace to have to deal with time values greater than
* 2^31 seconds (which uClibc cannot cope with yet)
*/
if ((bfin_read_RTC_STAT() & 0xC0000000) == 0xC0000000) {
printk(KERN_NOTICE "bfin-rtc: invalid date; resetting\n");
bfin_write_RTC_STAT(0);
}
#endif
time_sched_init(timer_interrupt);
}
|
