tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
mips: Use common i8253 clockevent
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20110609130622.133068765@linutronix.de
+3
-95
+1
arch/mips/Kconfig
+1
arch/mips/Kconfig
+2
-95
arch/mips/kernel/i8253.c
+2
-95
arch/mips/kernel/i8253.c
···
4
4
*/
5
5
#include <linux/clockchips.h>
6
6
#include <linux/i8253.h>
7
-
#include <linux/init.h>
8
-
#include <linux/interrupt.h>
9
-
#include <linux/jiffies.h>
10
7
#include <linux/module.h>
11
8
#include <linux/smp.h>
12
-
#include <linux/spinlock.h>
13
9
#include <linux/irq.h>
14
10
15
-
#include <asm/delay.h>
16
-
#include <asm/io.h>
17
11
#include <asm/time.h>
18
-
19
-
/*
20
-
* Initialize the PIT timer.
21
-
*
22
-
* This is also called after resume to bring the PIT into operation again.
23
-
*/
24
-
static void init_pit_timer(enum clock_event_mode mode,
25
-
struct clock_event_device *evt)
26
-
{
27
-
raw_spin_lock(&i8253_lock);
28
-
29
-
switch(mode) {
30
-
case CLOCK_EVT_MODE_PERIODIC:
31
-
/* binary, mode 2, LSB/MSB, ch 0 */
32
-
outb_p(0x34, PIT_MODE);
33
-
outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
34
-
outb(LATCH >> 8 , PIT_CH0); /* MSB */
35
-
break;
36
-
37
-
case CLOCK_EVT_MODE_SHUTDOWN:
38
-
case CLOCK_EVT_MODE_UNUSED:
39
-
if (evt->mode == CLOCK_EVT_MODE_PERIODIC ||
40
-
evt->mode == CLOCK_EVT_MODE_ONESHOT) {
41
-
outb_p(0x30, PIT_MODE);
42
-
outb_p(0, PIT_CH0);
43
-
outb_p(0, PIT_CH0);
44
-
}
45
-
break;
46
-
47
-
case CLOCK_EVT_MODE_ONESHOT:
48
-
/* One shot setup */
49
-
outb_p(0x38, PIT_MODE);
50
-
break;
51
-
52
-
case CLOCK_EVT_MODE_RESUME:
53
-
/* Nothing to do here */
54
-
break;
55
-
}
56
-
raw_spin_unlock(&i8253_lock);
57
-
}
58
-
59
-
/*
60
-
* Program the next event in oneshot mode
61
-
*
62
-
* Delta is given in PIT ticks
63
-
*/
64
-
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
65
-
{
66
-
raw_spin_lock(&i8253_lock);
67
-
outb_p(delta & 0xff , PIT_CH0); /* LSB */
68
-
outb(delta >> 8 , PIT_CH0); /* MSB */
69
-
raw_spin_unlock(&i8253_lock);
70
-
71
-
return 0;
72
-
}
73
-
74
-
/*
75
-
* On UP the PIT can serve all of the possible timer functions. On SMP systems
76
-
* it can be solely used for the global tick.
77
-
*
78
-
* The profiling and update capabilites are switched off once the local apic is
79
-
* registered. This mechanism replaces the previous #ifdef LOCAL_APIC -
80
-
* !using_apic_timer decisions in do_timer_interrupt_hook()
81
-
*/
82
-
static struct clock_event_device pit_clockevent = {
83
-
.name = "pit",
84
-
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
85
-
.set_mode = init_pit_timer,
86
-
.set_next_event = pit_next_event,
87
-
.irq = 0,
88
-
};
89
12
90
13
static irqreturn_t timer_interrupt(int irq, void *dev_id)
91
14
{
92
-
pit_clockevent.event_handler(&pit_clockevent);
15
+
i8253_clockevent.event_handler(&pit_clockevent);
93
16
94
17
return IRQ_HANDLED;
95
18
}
···
23
100
.name = "timer"
24
101
};
25
102
26
-
/*
27
-
* Initialize the conversion factor and the min/max deltas of the clock event
28
-
* structure and register the clock event source with the framework.
29
-
*/
30
103
void __init setup_pit_timer(void)
31
104
{
32
-
struct clock_event_device *cd = &pit_clockevent;
33
-
unsigned int cpu = smp_processor_id();
34
-
35
-
/*
36
-
* Start pit with the boot cpu mask and make it global after the
37
-
* IO_APIC has been initialized.
38
-
*/
39
-
cd->cpumask = cpumask_of(cpu);
40
-
clockevent_set_clock(cd, CLOCK_TICK_RATE);
41
-
cd->max_delta_ns = clockevent_delta2ns(0x7FFF, cd);
42
-
cd->min_delta_ns = clockevent_delta2ns(0xF, cd);
43
-
clockevents_register_device(cd);
44
-
105
+
clockevent_i8253_init(true);
45
106
setup_irq(0, &irq0);
46
107
}
47
108