time.c
3.69 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
/*
* linux/arch/arm/mach-w90x900/time.c
*
* Based on linux/arch/arm/plat-s3c24xx/time.c by Ben Dooks
*
* Copyright (c) 2009 Nuvoton technology corporation
* All rights reserved.
*
* Wan ZongShun <mcuos.com@gmail.com>
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <asm/mach-types.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include <mach/map.h>
#include <mach/regs-timer.h>
#include "nuc9xx.h"
#define RESETINT 0x1f
#define PERIOD (0x01 << 27)
#define ONESHOT (0x00 << 27)
#define COUNTEN (0x01 << 30)
#define INTEN (0x01 << 29)
#define TICKS_PER_SEC 100
#define PRESCALE 0x63 /* Divider = prescale + 1 */
#define TDR_SHIFT 24
static unsigned int timer0_load;
static void nuc900_clockevent_setmode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
unsigned int val;
val = __raw_readl(REG_TCSR0);
val &= ~(0x03 << 27);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
__raw_writel(timer0_load, REG_TICR0);
val |= (PERIOD | COUNTEN | INTEN | PRESCALE);
break;
case CLOCK_EVT_MODE_ONESHOT:
val |= (ONESHOT | COUNTEN | INTEN | PRESCALE);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
__raw_writel(val, REG_TCSR0);
}
static int nuc900_clockevent_setnextevent(unsigned long evt,
struct clock_event_device *clk)
{
unsigned int val;
__raw_writel(evt, REG_TICR0);
val = __raw_readl(REG_TCSR0);
val |= (COUNTEN | INTEN | PRESCALE);
__raw_writel(val, REG_TCSR0);
return 0;
}
static struct clock_event_device nuc900_clockevent_device = {
.name = "nuc900-timer0",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = nuc900_clockevent_setmode,
.set_next_event = nuc900_clockevent_setnextevent,
.rating = 300,
};
/*IRQ handler for the timer*/
static irqreturn_t nuc900_timer0_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &nuc900_clockevent_device;
__raw_writel(0x01, REG_TISR); /* clear TIF0 */
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction nuc900_timer0_irq = {
.name = "nuc900-timer0",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = nuc900_timer0_interrupt,
};
static void __init nuc900_clockevents_init(void)
{
unsigned int rate;
struct clk *clk = clk_get(NULL, "timer0");
BUG_ON(IS_ERR(clk));
__raw_writel(0x00, REG_TCSR0);
clk_enable(clk);
rate = clk_get_rate(clk) / (PRESCALE + 1);
timer0_load = (rate / TICKS_PER_SEC);
__raw_writel(RESETINT, REG_TISR);
setup_irq(IRQ_TIMER0, &nuc900_timer0_irq);
nuc900_clockevent_device.cpumask = cpumask_of(0);
clockevents_config_and_register(&nuc900_clockevent_device, rate,
0xf, 0xffffffff);
}
static void __init nuc900_clocksource_init(void)
{
unsigned int val;
unsigned int rate;
struct clk *clk = clk_get(NULL, "timer1");
BUG_ON(IS_ERR(clk));
__raw_writel(0x00, REG_TCSR1);
clk_enable(clk);
rate = clk_get_rate(clk) / (PRESCALE + 1);
__raw_writel(0xffffffff, REG_TICR1);
val = __raw_readl(REG_TCSR1);
val |= (COUNTEN | PERIOD | PRESCALE);
__raw_writel(val, REG_TCSR1);
clocksource_mmio_init(REG_TDR1, "nuc900-timer1", rate, 200,
TDR_SHIFT, clocksource_mmio_readl_down);
}
void __init nuc900_timer_init(void)
{
nuc900_clocksource_init();
nuc900_clockevents_init();
}