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
175
176
177
178
179
180
181
|
/*
* arch/arm/mach-orion/time.c
*
* Core time functions for Marvell Orion System On Chip
*
* Maintainer: Tzachi Perelstein <tzachi@marvell.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.
*/
#include <linux/kernel.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/mach/time.h>
#include <asm/arch/orion.h>
#include "common.h"
/*
* Timer0: clock_event_device, Tick.
* Timer1: clocksource, Free running.
* WatchDog: Not used.
*
* Timers are counting down.
*/
#define CLOCKEVENT 0
#define CLOCKSOURCE 1
/*
* Timers bits
*/
#define BRIDGE_INT_TIMER(x) (1 << ((x) + 1))
#define TIMER_EN(x) (1 << ((x) * 2))
#define TIMER_RELOAD_EN(x) (1 << (((x) * 2) + 1))
#define BRIDGE_INT_TIMER_WD (1 << 3)
#define TIMER_WD_EN (1 << 4)
#define TIMER_WD_RELOAD_EN (1 << 5)
static cycle_t orion_clksrc_read(void)
{
return (0xffffffff - orion_read(TIMER_VAL(CLOCKSOURCE)));
}
static struct clocksource orion_clksrc = {
.name = "orion_clocksource",
.shift = 20,
.rating = 300,
.read = orion_clksrc_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static int
orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev)
{
unsigned long flags;
if (delta == 0)
return -ETIME;
local_irq_save(flags);
/*
* Clear and enable timer interrupt bit
*/
orion_write(BRIDGE_CAUSE, ~BRIDGE_INT_TIMER(CLOCKEVENT));
orion_setbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKEVENT));
/*
* Setup new timer value
*/
orion_write(TIMER_VAL(CLOCKEVENT), delta);
/*
* Disable auto reload and kickoff the timer
*/
orion_clrbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKEVENT));
orion_setbits(TIMER_CTRL, TIMER_EN(CLOCKEVENT));
local_irq_restore(flags);
return 0;
}
static void
orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
unsigned long flags;
local_irq_save(flags);
if (mode == CLOCK_EVT_MODE_PERIODIC) {
/*
* Setup latch cycles in timer and enable reload interrupt.
*/
orion_write(TIMER_VAL_RELOAD(CLOCKEVENT), LATCH);
orion_write(TIMER_VAL(CLOCKEVENT), LATCH);
orion_setbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKEVENT));
orion_setbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKEVENT) |
TIMER_EN(CLOCKEVENT));
} else {
/*
* Disable timer and interrupt
*/
orion_clrbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKEVENT));
orion_write(BRIDGE_CAUSE, ~BRIDGE_INT_TIMER(CLOCKEVENT));
orion_clrbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKEVENT) |
TIMER_EN(CLOCKEVENT));
}
local_irq_restore(flags);
}
static struct clock_event_device orion_clkevt = {
.name = "orion_tick",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.rating = 300,
.cpumask = CPU_MASK_CPU0,
.set_next_event = orion_clkevt_next_event,
.set_mode = orion_clkevt_mode,
};
static irqreturn_t orion_timer_interrupt(int irq, void *dev_id)
{
/*
* Clear cause bit and do event
*/
orion_write(BRIDGE_CAUSE, ~BRIDGE_INT_TIMER(CLOCKEVENT));
orion_clkevt.event_handler(&orion_clkevt);
return IRQ_HANDLED;
}
static struct irqaction orion_timer_irq = {
.name = "orion_tick",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = orion_timer_interrupt
};
static void orion_timer_init(void)
{
/*
* Setup clocksource free running timer (no interrupt on reload)
*/
orion_write(TIMER_VAL(CLOCKSOURCE), 0xffffffff);
orion_write(TIMER_VAL_RELOAD(CLOCKSOURCE), 0xffffffff);
orion_clrbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKSOURCE));
orion_setbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKSOURCE) |
TIMER_EN(CLOCKSOURCE));
/*
* Register clocksource
*/
orion_clksrc.mult =
clocksource_hz2mult(CLOCK_TICK_RATE, orion_clksrc.shift);
clocksource_register(&orion_clksrc);
/*
* Connect and enable tick handler
*/
setup_irq(IRQ_ORION_BRIDGE, &orion_timer_irq);
/*
* Register clockevent
*/
orion_clkevt.mult =
div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, orion_clkevt.shift);
orion_clkevt.max_delta_ns =
clockevent_delta2ns(0xfffffffe, &orion_clkevt);
orion_clkevt.min_delta_ns =
clockevent_delta2ns(1, &orion_clkevt);
clockevents_register_device(&orion_clkevt);
}
struct sys_timer orion_timer = {
.init = orion_timer_init,
};
|
