summaryrefslogtreecommitdiff
path: root/arch/mips/jazz/irq.c
blob: 835b056cea36c42c835cdadfdcfca47ae668611e (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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1992 Linus Torvalds
 * Copyright (C) 1994 - 2001, 2003 Ralf Baechle
 */
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>

#include <asm/irq_cpu.h>
#include <asm/i8259.h>
#include <asm/io.h>
#include <asm/jazz.h>
#include <asm/pgtable.h>

static DEFINE_SPINLOCK(r4030_lock);

static void enable_r4030_irq(unsigned int irq)
{
	unsigned int mask = 1 << (irq - JAZZ_IRQ_START);
	unsigned long flags;

	spin_lock_irqsave(&r4030_lock, flags);
	mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
	spin_unlock_irqrestore(&r4030_lock, flags);
}

void disable_r4030_irq(unsigned int irq)
{
	unsigned int mask = ~(1 << (irq - JAZZ_IRQ_START));
	unsigned long flags;

	spin_lock_irqsave(&r4030_lock, flags);
	mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
	spin_unlock_irqrestore(&r4030_lock, flags);
}

static struct irq_chip r4030_irq_type = {
	.name = "R4030",
	.ack = disable_r4030_irq,
	.mask = disable_r4030_irq,
	.mask_ack = disable_r4030_irq,
	.unmask = enable_r4030_irq,
};

void __init init_r4030_ints(void)
{
	int i;

	for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++)
		set_irq_chip_and_handler(i, &r4030_irq_type, handle_level_irq);

	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
	r4030_read_reg16(JAZZ_IO_IRQ_SOURCE);		/* clear pending IRQs */
	r4030_read_reg32(JAZZ_R4030_INVAL_ADDR);	/* clear error bits */
}

/*
 * On systems with i8259-style interrupt controllers we assume for
 * driver compatibility reasons interrupts 0 - 15 to be the i8259
 * interrupts even if the hardware uses a different interrupt numbering.
 */
void __init arch_init_irq(void)
{
	/*
	 * this is a hack to get back the still needed wired mapping
	 * killed by init_mm()
	 */

	/* Map 0xe0000000 -> 0x0:800005C0, 0xe0010000 -> 0x1:30000580 */
	add_wired_entry(0x02000017, 0x03c00017, 0xe0000000, PM_64K);
	/* Map 0xe2000000 -> 0x0:900005C0, 0xe3010000 -> 0x0:910005C0 */
	add_wired_entry(0x02400017, 0x02440017, 0xe2000000, PM_16M);
	/* Map 0xe4000000 -> 0x0:600005C0, 0xe4100000 -> 400005C0 */
	add_wired_entry(0x01800017, 0x01000017, 0xe4000000, PM_4M);

	init_i8259_irqs();			/* Integrated i8259  */
	mips_cpu_irq_init();
	init_r4030_ints();

	change_c0_status(ST0_IM, IE_IRQ2 | IE_IRQ1);
}

asmlinkage void plat_irq_dispatch(void)
{
	unsigned int pending = read_c0_cause() & read_c0_status();
	unsigned int irq;

	if (pending & IE_IRQ4) {
		r4030_read_reg32(JAZZ_TIMER_REGISTER);
		do_IRQ(JAZZ_TIMER_IRQ);
	} else if (pending & IE_IRQ2)
		do_IRQ(r4030_read_reg32(JAZZ_EISA_IRQ_ACK));
	else if (pending & IE_IRQ1) {
		irq = *(volatile u8 *)JAZZ_IO_IRQ_SOURCE >> 2;
		if (likely(irq > 0))
			do_IRQ(irq + JAZZ_IRQ_START - 1);
		else
			panic("Unimplemented loc_no_irq handler");
	}
}

static void r4030_set_mode(enum clock_event_mode mode,
                           struct clock_event_device *evt)
{
	/* Nothing to do ...  */
}

struct clock_event_device r4030_clockevent = {
	.name		= "r4030",
	.features	= CLOCK_EVT_FEAT_PERIODIC,
	.rating		= 100,
	.irq		= JAZZ_TIMER_IRQ,
	.cpumask	= CPU_MASK_CPU0,
	.set_mode	= r4030_set_mode,
};

static irqreturn_t r4030_timer_interrupt(int irq, void *dev_id)
{
	r4030_clockevent.event_handler(&r4030_clockevent);

	return IRQ_HANDLED;
}

static struct irqaction r4030_timer_irqaction = {
	.handler	= r4030_timer_interrupt,
	.flags		= IRQF_DISABLED,
	.mask		= CPU_MASK_CPU0,
	.name		= "timer",
};

void __init plat_timer_setup(struct irqaction *ignored)
{
	struct irqaction *irq = &r4030_timer_irqaction;

	BUG_ON(HZ != 100);

	/*
	 * Set clock to 100Hz.
	 *
	 * The R4030 timer receives an input clock of 1kHz which is divieded by
	 * a programmable 4-bit divider.  This makes it fairly inflexible.
	 */
	r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9);
	setup_irq(JAZZ_TIMER_IRQ, irq);

	clockevents_register_device(&r4030_clockevent);
}