aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-aaec2000/core.c
blob: fc145b3768fab5a4431f59ec45ac57536456c420 (plain)
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
/*
 *  linux/arch/arm/mach-aaec2000/core.c
 *
 *  Code common to all AAEC-2000 machines
 *
 *  Copyright (c) 2005 Nicolas Bellido Y Ortega
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/signal.h>

#include <asm/hardware.h>
#include <asm/irq.h>

#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include <asm/mach/map.h>

/*
 * Common I/O mapping:
 *
 * Static virtual address mappings are as follow:
 *
 * 0xf8000000-0xf8001ffff: Devices connected to APB bus
 * 0xf8002000-0xf8003ffff: Devices connected to AHB bus
 *
 * Below 0xe8000000 is reserved for vm allocation.
 *
 * The machine specific code must provide the extra mapping beside the
 * default mapping provided here.
 */
static struct map_desc standard_io_desc[] __initdata = {
 /* virtual         physical       length           type */
  { VIO_APB_BASE,   PIO_APB_BASE,  IO_APB_LENGTH,   MT_DEVICE },
  { VIO_AHB_BASE,   PIO_AHB_BASE,  IO_AHB_LENGTH,   MT_DEVICE }
};

void __init aaec2000_map_io(void)
{
	iotable_init(standard_io_desc, ARRAY_SIZE(standard_io_desc));
}

/*
 * Interrupt handling routines
 */
static void aaec2000_int_ack(unsigned int irq)
{
	IRQ_INTSR = 1 << irq;
}

static void aaec2000_int_mask(unsigned int irq)
{
	IRQ_INTENC |= (1 << irq);
}

static void aaec2000_int_unmask(unsigned int irq)
{
	IRQ_INTENS |= (1 << irq);
}

static struct irqchip aaec2000_irq_chip = {
	.ack	= aaec2000_int_ack,
	.mask	= aaec2000_int_mask,
	.unmask	= aaec2000_int_unmask,
};

void __init aaec2000_init_irq(void)
{
	unsigned int i;

	for (i = 0; i < NR_IRQS; i++) {
		set_irq_handler(i, do_level_IRQ);
		set_irq_chip(i, &aaec2000_irq_chip);
		set_irq_flags(i, IRQF_VALID);
	}

	/* Disable all interrupts */
	IRQ_INTENC = 0xffffffff;

	/* Clear any pending interrupts */
	IRQ_INTSR = IRQ_INTSR;
}

/*
 * Time keeping
 */
/* IRQs are disabled before entering here from do_gettimeofday() */
static unsigned long aaec2000_gettimeoffset(void)
{
	unsigned long ticks_to_match, elapsed, usec;

	/* Get ticks before next timer match */
	ticks_to_match = TIMER1_LOAD - TIMER1_VAL;

	/* We need elapsed ticks since last match */
	elapsed = LATCH - ticks_to_match;

	/* Now, convert them to usec */
	usec = (unsigned long)(elapsed * (tick_nsec / 1000))/LATCH;

	return usec;
}

/* We enter here with IRQs enabled */
static irqreturn_t
aaec2000_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	/* TODO: Check timer accuracy */
	write_seqlock(&xtime_lock);

	timer_tick(regs);
	TIMER1_CLEAR = 1;

	write_sequnlock(&xtime_lock);

	return IRQ_HANDLED;
}

static struct irqaction aaec2000_timer_irq = {
	.name		= "AAEC-2000 Timer Tick",
	.flags		= SA_INTERRUPT,
	.handler	= aaec2000_timer_interrupt
};

static void __init aaec2000_timer_init(void)
{
	/* Disable timer 1 */
	TIMER1_CTRL = 0;

	/* We have somehow to generate a 100Hz clock.
	 * We then use the 508KHz timer in periodic mode.
	 */
	TIMER1_LOAD = LATCH;
	TIMER1_CLEAR = 1; /* Clear interrupt */

	setup_irq(INT_TMR1_OFL, &aaec2000_timer_irq);

	TIMER1_CTRL = TIMER_CTRL_ENABLE |
	                TIMER_CTRL_PERIODIC |
	                TIMER_CTRL_CLKSEL_508K;
}

struct sys_timer aaec2000_timer = {
	.init		= aaec2000_timer_init,
	.offset		= aaec2000_gettimeoffset,
};