time.c
4.48 KB
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
/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 platform time support
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/clockchips.h>
#include <linux/sched_clock.h>
#include <asm/mach-jz4740/clock.h>
#include <asm/mach-jz4740/irq.h>
#include <asm/mach-jz4740/timer.h>
#include <asm/time.h>
#include "clock.h"
#define TIMER_CLOCKEVENT 0
#define TIMER_CLOCKSOURCE 1
static uint16_t jz4740_jiffies_per_tick;
static cycle_t jz4740_clocksource_read(struct clocksource *cs)
{
return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
}
static struct clocksource jz4740_clocksource = {
.name = "jz4740-timer",
.rating = 200,
.read = jz4740_clocksource_read,
.mask = CLOCKSOURCE_MASK(16),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u64 notrace jz4740_read_sched_clock(void)
{
return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
}
static irqreturn_t jz4740_clockevent_irq(int irq, void *devid)
{
struct clock_event_device *cd = devid;
jz4740_timer_ack_full(TIMER_CLOCKEVENT);
if (!clockevent_state_periodic(cd))
jz4740_timer_disable(TIMER_CLOCKEVENT);
cd->event_handler(cd);
return IRQ_HANDLED;
}
static int jz4740_clockevent_set_periodic(struct clock_event_device *evt)
{
jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
jz4740_timer_enable(TIMER_CLOCKEVENT);
return 0;
}
static int jz4740_clockevent_resume(struct clock_event_device *evt)
{
jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
jz4740_timer_enable(TIMER_CLOCKEVENT);
return 0;
}
static int jz4740_clockevent_shutdown(struct clock_event_device *evt)
{
jz4740_timer_disable(TIMER_CLOCKEVENT);
return 0;
}
static int jz4740_clockevent_set_next(unsigned long evt,
struct clock_event_device *cd)
{
jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
jz4740_timer_set_period(TIMER_CLOCKEVENT, evt);
jz4740_timer_enable(TIMER_CLOCKEVENT);
return 0;
}
static struct clock_event_device jz4740_clockevent = {
.name = "jz4740-timer",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = jz4740_clockevent_set_next,
.set_state_shutdown = jz4740_clockevent_shutdown,
.set_state_periodic = jz4740_clockevent_set_periodic,
.set_state_oneshot = jz4740_clockevent_shutdown,
.tick_resume = jz4740_clockevent_resume,
.rating = 200,
#ifdef CONFIG_MACH_JZ4740
.irq = JZ4740_IRQ_TCU0,
#endif
#ifdef CONFIG_MACH_JZ4780
.irq = JZ4780_IRQ_TCU2,
#endif
};
static struct irqaction timer_irqaction = {
.handler = jz4740_clockevent_irq,
.flags = IRQF_PERCPU | IRQF_TIMER,
.name = "jz4740-timerirq",
.dev_id = &jz4740_clockevent,
};
void __init plat_time_init(void)
{
int ret;
uint32_t clk_rate;
uint16_t ctrl;
struct clk *ext_clk;
of_clk_init(NULL);
jz4740_timer_init();
ext_clk = clk_get(NULL, "ext");
if (IS_ERR(ext_clk))
panic("unable to get ext clock");
clk_rate = clk_get_rate(ext_clk) >> 4;
clk_put(ext_clk);
jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ);
clockevent_set_clock(&jz4740_clockevent, clk_rate);
jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent);
jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent);
jz4740_clockevent.cpumask = cpumask_of(0);
clockevents_register_device(&jz4740_clockevent);
ret = clocksource_register_hz(&jz4740_clocksource, clk_rate);
if (ret)
printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
sched_clock_register(jz4740_read_sched_clock, 16, clk_rate);
setup_irq(jz4740_clockevent.irq, &timer_irqaction);
ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT;
jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl);
jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl);
jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff);
jz4740_timer_enable(TIMER_CLOCKEVENT);
jz4740_timer_enable(TIMER_CLOCKSOURCE);
}