summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/irq.c
blob: 1db121f437d2f0e7c4367c401956ac810a9bc9a2 (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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*
 * linux/arch/arm/mach-omap2/irq.c
 *
 * Interrupt handler for OMAP2 boards.
 *
 * Copyright (C) 2005 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *
 * 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.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <asm/mach/irq.h>


/* selected INTC register offsets */

#define INTC_REVISION		0x0000
#define INTC_SYSCONFIG		0x0010
#define INTC_SYSSTATUS		0x0014
#define INTC_SIR		0x0040
#define INTC_CONTROL		0x0048
#define INTC_MIR_CLEAR0		0x0088
#define INTC_MIR_SET0		0x008c
#define INTC_PENDING_IRQ0	0x0098
/* Number of IRQ state bits in each MIR register */
#define IRQ_BITS_PER_REG	32

/*
 * OMAP2 has a number of different interrupt controllers, each interrupt
 * controller is identified as its own "bank". Register definitions are
 * fairly consistent for each bank, but not all registers are implemented
 * for each bank.. when in doubt, consult the TRM.
 */
static struct omap_irq_bank {
	void __iomem *base_reg;
	unsigned int nr_irqs;
} __attribute__ ((aligned(4))) irq_banks[] = {
	{
		/* MPU INTC */
		.base_reg	= 0,
		.nr_irqs	= 96,
	},
};

/* INTC bank register get/set */

static void intc_bank_write_reg(u32 val, struct omap_irq_bank *bank, u16 reg)
{
	__raw_writel(val, bank->base_reg + reg);
}

static u32 intc_bank_read_reg(struct omap_irq_bank *bank, u16 reg)
{
	return __raw_readl(bank->base_reg + reg);
}

static int previous_irq;

/*
 * On 34xx we can get occasional spurious interrupts if the ack from
 * an interrupt handler does not get posted before we unmask. Warn about
 * the interrupt handlers that need to flush posted writes.
 */
static int omap_check_spurious(unsigned int irq)
{
	u32 sir, spurious;

	sir = intc_bank_read_reg(&irq_banks[0], INTC_SIR);
	spurious = sir >> 7;

	if (spurious) {
		printk(KERN_WARNING "Spurious irq %i: 0x%08x, please flush "
					"posted write for irq %i\n",
					irq, sir, previous_irq);
		return spurious;
	}

	return 0;
}

/* XXX: FIQ and additional INTC support (only MPU at the moment) */
static void omap_ack_irq(unsigned int irq)
{
	intc_bank_write_reg(0x1, &irq_banks[0], INTC_CONTROL);
}

static void omap_mask_irq(unsigned int irq)
{
	int offset = irq & (~(IRQ_BITS_PER_REG - 1));

	if (cpu_is_omap34xx()) {
		int spurious = 0;

		/*
		 * INT_34XX_GPT12_IRQ is also the spurious irq. Maybe because
		 * it is the highest irq number?
		 */
		if (irq == INT_34XX_GPT12_IRQ)
			spurious = omap_check_spurious(irq);

		if (!spurious)
			previous_irq = irq;
	}

	irq &= (IRQ_BITS_PER_REG - 1);

	intc_bank_write_reg(1 << irq, &irq_banks[0], INTC_MIR_SET0 + offset);
}

static void omap_unmask_irq(unsigned int irq)
{
	int offset = irq & (~(IRQ_BITS_PER_REG - 1));

	irq &= (IRQ_BITS_PER_REG - 1);

	intc_bank_write_reg(1 << irq, &irq_banks[0], INTC_MIR_CLEAR0 + offset);
}

static void omap_mask_ack_irq(unsigned int irq)
{
	omap_mask_irq(irq);
	omap_ack_irq(irq);
}

static struct irq_chip omap_irq_chip = {
	.name	= "INTC",
	.ack	= omap_mask_ack_irq,
	.mask	= omap_mask_irq,
	.unmask	= omap_unmask_irq,
};

static void __init omap_irq_bank_init_one(struct omap_irq_bank *bank)
{
	unsigned long tmp;

	tmp = intc_bank_read_reg(bank, INTC_REVISION) & 0xff;
	printk(KERN_INFO "IRQ: Found an INTC at 0x%p "
			 "(revision %ld.%ld) with %d interrupts\n",
			 bank->base_reg, tmp >> 4, tmp & 0xf, bank->nr_irqs);

	tmp = intc_bank_read_reg(bank, INTC_SYSCONFIG);
	tmp |= 1 << 1;	/* soft reset */
	intc_bank_write_reg(tmp, bank, INTC_SYSCONFIG);

	while (!(intc_bank_read_reg(bank, INTC_SYSSTATUS) & 0x1))
		/* Wait for reset to complete */;

	/* Enable autoidle */
	intc_bank_write_reg(1 << 0, bank, INTC_SYSCONFIG);
}

int omap_irq_pending(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
		struct omap_irq_bank *bank = irq_banks + i;
		int irq;

		for (irq = 0; irq < bank->nr_irqs; irq += 32)
			if (intc_bank_read_reg(bank, INTC_PENDING_IRQ0 +
					       ((irq >> 5) << 5)))
				return 1;
	}
	return 0;
}

void __init omap_init_irq(void)
{
	unsigned long nr_of_irqs = 0;
	unsigned int nr_banks = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
		unsigned long base;
		struct omap_irq_bank *bank = irq_banks + i;

		if (cpu_is_omap24xx())
			base = OMAP24XX_IC_BASE;
		else if (cpu_is_omap34xx())
			base = OMAP34XX_IC_BASE;

		/* Static mapping, never released */
		bank->base_reg = ioremap(base, SZ_4K);
		if (!bank->base_reg) {
			printk(KERN_ERR "Could not ioremap irq bank%i\n", i);
			continue;
		}

		omap_irq_bank_init_one(bank);

		nr_of_irqs += bank->nr_irqs;
		nr_banks++;
	}

	printk(KERN_INFO "Total of %ld interrupts on %d active controller%s\n",
	       nr_of_irqs, nr_banks, nr_banks > 1 ? "s" : "");

	for (i = 0; i < nr_of_irqs; i++) {
		set_irq_chip(i, &omap_irq_chip);
		set_irq_handler(i, handle_level_irq);
		set_irq_flags(i, IRQF_VALID);
	}
}