5113f6f70
 김현기
kernel add
|
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
|
/*
* Marvell Orion SoC timer handling.
*
* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* Timer 0 is used as free-running clocksource, while timer 1 is
* used as clock_event_device.
*/
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/spinlock.h>
#include <linux/sched_clock.h>
#define TIMER_CTRL 0x00
#define TIMER0_EN BIT(0)
#define TIMER0_RELOAD_EN BIT(1)
#define TIMER1_EN BIT(2)
#define TIMER1_RELOAD_EN BIT(3)
#define TIMER0_RELOAD 0x10
#define TIMER0_VAL 0x14
#define TIMER1_RELOAD 0x18
#define TIMER1_VAL 0x1c
#define ORION_ONESHOT_MIN 1
#define ORION_ONESHOT_MAX 0xfffffffe
static void __iomem *timer_base;
/*
* Free-running clocksource handling.
*/
static u64 notrace orion_read_sched_clock(void)
{
return ~readl(timer_base + TIMER0_VAL);
}
/*
* Clockevent handling.
*/
static u32 ticks_per_jiffy;
static int orion_clkevt_next_event(unsigned long delta,
struct clock_event_device *dev)
{
/* setup and enable one-shot timer */
writel(delta, timer_base + TIMER1_VAL);
atomic_io_modify(timer_base + TIMER_CTRL,
TIMER1_RELOAD_EN | TIMER1_EN, TIMER1_EN);
return 0;
}
static int orion_clkevt_shutdown(struct clock_event_device *dev)
{
/* disable timer */
atomic_io_modify(timer_base + TIMER_CTRL,
TIMER1_RELOAD_EN | TIMER1_EN, 0);
return 0;
}
static int orion_clkevt_set_periodic(struct clock_event_device *dev)
{
/* setup and enable periodic timer at 1/HZ intervals */
writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD);
writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL);
atomic_io_modify(timer_base + TIMER_CTRL,
TIMER1_RELOAD_EN | TIMER1_EN,
TIMER1_RELOAD_EN | TIMER1_EN);
return 0;
}
static struct clock_event_device orion_clkevt = {
.name = "orion_event",
.features = CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_PERIODIC,
.shift = 32,
.rating = 300,
.set_next_event = orion_clkevt_next_event,
.set_state_shutdown = orion_clkevt_shutdown,
.set_state_periodic = orion_clkevt_set_periodic,
.set_state_oneshot = orion_clkevt_shutdown,
.tick_resume = orion_clkevt_shutdown,
};
static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id)
{
orion_clkevt.event_handler(&orion_clkevt);
return IRQ_HANDLED;
}
static struct irqaction orion_clkevt_irq = {
.name = "orion_event",
.flags = IRQF_TIMER,
.handler = orion_clkevt_irq_handler,
};
static void __init orion_timer_init(struct device_node *np)
{
struct clk *clk;
int irq;
/* timer registers are shared with watchdog timer */
timer_base = of_iomap(np, 0);
if (!timer_base)
panic("%s: unable to map resource
", np->name);
clk = of_clk_get(np, 0);
if (IS_ERR(clk))
panic("%s: unable to get clk
", np->name);
clk_prepare_enable(clk);
/* we are only interested in timer1 irq */
irq = irq_of_parse_and_map(np, 1);
if (irq <= 0)
panic("%s: unable to parse timer1 irq
", np->name);
/* setup timer0 as free-running clocksource */
writel(~0, timer_base + TIMER0_VAL);
writel(~0, timer_base + TIMER0_RELOAD);
atomic_io_modify(timer_base + TIMER_CTRL,
TIMER0_RELOAD_EN | TIMER0_EN,
TIMER0_RELOAD_EN | TIMER0_EN);
clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
clk_get_rate(clk), 300, 32,
clocksource_mmio_readl_down);
sched_clock_register(orion_read_sched_clock, 32, clk_get_rate(clk));
/* setup timer1 as clockevent timer */
if (setup_irq(irq, &orion_clkevt_irq))
panic("%s: unable to setup irq
", np->name);
ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
orion_clkevt.cpumask = cpumask_of(0);
orion_clkevt.irq = irq;
clockevents_config_and_register(&orion_clkevt, clk_get_rate(clk),
ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
}
CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);
|