summaryrefslogtreecommitdiff
path: root/drivers/irqchip/irq-goldfish-pic.c
blob: 2a92f03c73e48c67a70057996b5f20e84ac34c2e (plain) (blame)
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
/*
 * Driver for MIPS Goldfish Programmable Interrupt Controller.
 *
 * Author: Miodrag Dinic <miodrag.dinic@mips.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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

#define GFPIC_NR_IRQS			32

/* 8..39 Cascaded Goldfish PIC interrupts */
#define GFPIC_IRQ_BASE			8

#define GFPIC_REG_IRQ_PENDING		0x04
#define GFPIC_REG_IRQ_DISABLE_ALL	0x08
#define GFPIC_REG_IRQ_DISABLE		0x0c
#define GFPIC_REG_IRQ_ENABLE		0x10

struct goldfish_pic_data {
	void __iomem *base;
	struct irq_domain *irq_domain;
};

static void goldfish_pic_cascade(struct irq_desc *desc)
{
	struct goldfish_pic_data *gfpic = irq_desc_get_handler_data(desc);
	struct irq_chip *host_chip = irq_desc_get_chip(desc);
	u32 pending, hwirq, virq;

	chained_irq_enter(host_chip, desc);

	pending = readl(gfpic->base + GFPIC_REG_IRQ_PENDING);
	while (pending) {
		hwirq = __fls(pending);
		virq = irq_linear_revmap(gfpic->irq_domain, hwirq);
		generic_handle_irq(virq);
		pending &= ~(1 << hwirq);
	}

	chained_irq_exit(host_chip, desc);
}

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

static int __init goldfish_pic_of_init(struct device_node *of_node,
				       struct device_node *parent)
{
	struct goldfish_pic_data *gfpic;
	struct irq_chip_generic *gc;
	struct irq_chip_type *ct;
	unsigned int parent_irq;
	int ret = 0;

	gfpic = kzalloc(sizeof(*gfpic), GFP_KERNEL);
	if (!gfpic) {
		ret = -ENOMEM;
		goto out_err;
	}

	parent_irq = irq_of_parse_and_map(of_node, 0);
	if (!parent_irq) {
		pr_err("Failed to map parent IRQ!\n");
		ret = -EINVAL;
		goto out_free;
	}

	gfpic->base = of_iomap(of_node, 0);
	if (!gfpic->base) {
		pr_err("Failed to map base address!\n");
		ret = -ENOMEM;
		goto out_unmap_irq;
	}

	/* Mask interrupts. */
	writel(1, gfpic->base + GFPIC_REG_IRQ_DISABLE_ALL);

	gc = irq_alloc_generic_chip("GFPIC", 1, GFPIC_IRQ_BASE, gfpic->base,
				    handle_level_irq);
	if (!gc) {
		pr_err("Failed to allocate chip structures!\n");
		ret = -ENOMEM;
		goto out_iounmap;
	}

	ct = gc->chip_types;
	ct->regs.enable = GFPIC_REG_IRQ_ENABLE;
	ct->regs.disable = GFPIC_REG_IRQ_DISABLE;
	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
	ct->chip.irq_mask = irq_gc_mask_disable_reg;

	irq_setup_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS), 0,
			       IRQ_NOPROBE | IRQ_LEVEL, 0);

	gfpic->irq_domain = irq_domain_add_legacy(of_node, GFPIC_NR_IRQS,
						  GFPIC_IRQ_BASE, 0,
						  &goldfish_irq_domain_ops,
						  NULL);
	if (!gfpic->irq_domain) {
		pr_err("Failed to add irqdomain!\n");
		ret = -ENOMEM;
		goto out_destroy_generic_chip;
	}

	irq_set_chained_handler_and_data(parent_irq,
					 goldfish_pic_cascade, gfpic);

	pr_info("Successfully registered.\n");
	return 0;

out_destroy_generic_chip:
	irq_destroy_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS),
				 IRQ_NOPROBE | IRQ_LEVEL, 0);
out_iounmap:
	iounmap(gfpic->base);
out_unmap_irq:
	irq_dispose_mapping(parent_irq);
out_free:
	kfree(gfpic);
out_err:
	pr_err("Failed to initialize! (errno = %d)\n", ret);
	return ret;
}

IRQCHIP_DECLARE(google_gf_pic, "google,goldfish-pic", goldfish_pic_of_init);