aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/ralink/irq.c
blob: 8c624a8b9ea29f5611abceb531de09c865e46b7c (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
/*
 * 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.
 *
 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
 */

#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>

#include <asm/irq_cpu.h>
#include <asm/mipsregs.h>

#include "common.h"

#define INTC_INT_GLOBAL		BIT(31)

#define RALINK_CPU_IRQ_INTC	(MIPS_CPU_IRQ_BASE + 2)
#define RALINK_CPU_IRQ_PCI	(MIPS_CPU_IRQ_BASE + 4)
#define RALINK_CPU_IRQ_FE	(MIPS_CPU_IRQ_BASE + 5)
#define RALINK_CPU_IRQ_WIFI	(MIPS_CPU_IRQ_BASE + 6)
#define RALINK_CPU_IRQ_COUNTER	(MIPS_CPU_IRQ_BASE + 7)

/* we have a cascade of 8 irqs */
#define RALINK_INTC_IRQ_BASE	8

/* we have 32 SoC irqs */
#define RALINK_INTC_IRQ_COUNT	32

#define RALINK_INTC_IRQ_PERFC   (RALINK_INTC_IRQ_BASE + 9)

enum rt_intc_regs_enum {
	INTC_REG_STATUS0 = 0,
	INTC_REG_STATUS1,
	INTC_REG_TYPE,
	INTC_REG_RAW_STATUS,
	INTC_REG_ENABLE,
	INTC_REG_DISABLE,
};

static u32 rt_intc_regs[] = {
	[INTC_REG_STATUS0] = 0x00,
	[INTC_REG_STATUS1] = 0x04,
	[INTC_REG_TYPE] = 0x20,
	[INTC_REG_RAW_STATUS] = 0x30,
	[INTC_REG_ENABLE] = 0x34,
	[INTC_REG_DISABLE] = 0x38,
};

static void __iomem *rt_intc_membase;

static int rt_perfcount_irq;

static inline void rt_intc_w32(u32 val, unsigned reg)
{
	__raw_writel(val, rt_intc_membase + rt_intc_regs[reg]);
}

static inline u32 rt_intc_r32(unsigned reg)
{
	return __raw_readl(rt_intc_membase + rt_intc_regs[reg]);
}

static void ralink_intc_irq_unmask(struct irq_data *d)
{
	rt_intc_w32(BIT(d->hwirq), INTC_REG_ENABLE);
}

static void ralink_intc_irq_mask(struct irq_data *d)
{
	rt_intc_w32(BIT(d->hwirq), INTC_REG_DISABLE);
}

static struct irq_chip ralink_intc_irq_chip = {
	.name		= "INTC",
	.irq_unmask	= ralink_intc_irq_unmask,
	.irq_mask	= ralink_intc_irq_mask,
	.irq_mask_ack	= ralink_intc_irq_mask,
};

int get_c0_perfcount_int(void)
{
	return rt_perfcount_irq;
}
EXPORT_SYMBOL_GPL(get_c0_perfcount_int);

unsigned int get_c0_compare_int(void)
{
	return CP0_LEGACY_COMPARE_IRQ;
}

static void ralink_intc_irq_handler(unsigned int irq, struct irq_desc *desc)
{
	u32 pending = rt_intc_r32(INTC_REG_STATUS0);

	if (pending) {
		struct irq_domain *domain = irq_desc_get_handler_data(desc);
		generic_handle_irq(irq_find_mapping(domain, __ffs(pending)));
	} else {
		spurious_interrupt();
	}
}

asmlinkage void plat_irq_dispatch(void)
{
	unsigned long pending;

	pending = read_c0_status() & read_c0_cause() & ST0_IM;

	if (pending & STATUSF_IP7)
		do_IRQ(RALINK_CPU_IRQ_COUNTER);

	else if (pending & STATUSF_IP5)
		do_IRQ(RALINK_CPU_IRQ_FE);

	else if (pending & STATUSF_IP6)
		do_IRQ(RALINK_CPU_IRQ_WIFI);

	else if (pending & STATUSF_IP4)
		do_IRQ(RALINK_CPU_IRQ_PCI);

	else if (pending & STATUSF_IP2)
		do_IRQ(RALINK_CPU_IRQ_INTC);

	else
		spurious_interrupt();
}

static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
	irq_set_chip_and_handler(irq, &ralink_intc_irq_chip, handle_level_irq);

	return 0;
}

static const struct irq_domain_ops irq_domain_ops = {
	.xlate = irq_domain_xlate_onecell,
	.map = intc_map,
};

static int __init intc_of_init(struct device_node *node,
			       struct device_node *parent)
{
	struct resource res;
	struct irq_domain *domain;
	int irq;

	if (!of_property_read_u32_array(node, "ralink,intc-registers",
					rt_intc_regs, 6))
		pr_info("intc: using register map from devicetree\n");

	irq = irq_of_parse_and_map(node, 0);
	if (!irq)
		panic("Failed to get INTC IRQ");

	if (of_address_to_resource(node, 0, &res))
		panic("Failed to get intc memory range");

	if (request_mem_region(res.start, resource_size(&res),
				res.name) < 0)
		pr_err("Failed to request intc memory");

	rt_intc_membase = ioremap_nocache(res.start,
					resource_size(&res));
	if (!rt_intc_membase)
		panic("Failed to remap intc memory");

	/* disable all interrupts */
	rt_intc_w32(~0, INTC_REG_DISABLE);

	/* route all INTC interrupts to MIPS HW0 interrupt */
	rt_intc_w32(0, INTC_REG_TYPE);

	domain = irq_domain_add_legacy(node, RALINK_INTC_IRQ_COUNT,
			RALINK_INTC_IRQ_BASE, 0, &irq_domain_ops, NULL);
	if (!domain)
		panic("Failed to add irqdomain");

	rt_intc_w32(INTC_INT_GLOBAL, INTC_REG_ENABLE);

	irq_set_chained_handler_and_data(irq, ralink_intc_irq_handler, domain);

	/* tell the kernel which irq is used for performance monitoring */
	rt_perfcount_irq = irq_create_mapping(domain, 9);

	return 0;
}

static struct of_device_id __initdata of_irq_ids[] = {
	{ .compatible = "mti,cpu-interrupt-controller", .data = mips_cpu_irq_of_init },
	{ .compatible = "ralink,rt2880-intc", .data = intc_of_init },
	{},
};

void __init arch_init_irq(void)
{
	of_irq_init(of_irq_ids);
}