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7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/interrupt.h>
11#include <linux/irq.h>
12#include <linux/irqchip.h>
13#include <linux/irqchip/chained_irq.h>
14#include <linux/irqdomain.h>
15#include <linux/of_address.h>
16#include <linux/of_irq.h>
17
18#define GFPIC_NR_IRQS 32
19
20
21#define GFPIC_IRQ_BASE 8
22
23#define GFPIC_REG_IRQ_PENDING 0x04
24#define GFPIC_REG_IRQ_DISABLE_ALL 0x08
25#define GFPIC_REG_IRQ_DISABLE 0x0c
26#define GFPIC_REG_IRQ_ENABLE 0x10
27
28struct goldfish_pic_data {
29 void __iomem *base;
30 struct irq_domain *irq_domain;
31};
32
33static void goldfish_pic_cascade(struct irq_desc *desc)
34{
35 struct goldfish_pic_data *gfpic = irq_desc_get_handler_data(desc);
36 struct irq_chip *host_chip = irq_desc_get_chip(desc);
37 u32 pending, hwirq, virq;
38
39 chained_irq_enter(host_chip, desc);
40
41 pending = readl(gfpic->base + GFPIC_REG_IRQ_PENDING);
42 while (pending) {
43 hwirq = __fls(pending);
44 virq = irq_linear_revmap(gfpic->irq_domain, hwirq);
45 generic_handle_irq(virq);
46 pending &= ~(1 << hwirq);
47 }
48
49 chained_irq_exit(host_chip, desc);
50}
51
52static const struct irq_domain_ops goldfish_irq_domain_ops = {
53 .xlate = irq_domain_xlate_onecell,
54};
55
56static int __init goldfish_pic_of_init(struct device_node *of_node,
57 struct device_node *parent)
58{
59 struct goldfish_pic_data *gfpic;
60 struct irq_chip_generic *gc;
61 struct irq_chip_type *ct;
62 unsigned int parent_irq;
63 int ret = 0;
64
65 gfpic = kzalloc(sizeof(*gfpic), GFP_KERNEL);
66 if (!gfpic) {
67 ret = -ENOMEM;
68 goto out_err;
69 }
70
71 parent_irq = irq_of_parse_and_map(of_node, 0);
72 if (!parent_irq) {
73 pr_err("Failed to map parent IRQ!\n");
74 ret = -EINVAL;
75 goto out_free;
76 }
77
78 gfpic->base = of_iomap(of_node, 0);
79 if (!gfpic->base) {
80 pr_err("Failed to map base address!\n");
81 ret = -ENOMEM;
82 goto out_unmap_irq;
83 }
84
85
86 writel(1, gfpic->base + GFPIC_REG_IRQ_DISABLE_ALL);
87
88 gc = irq_alloc_generic_chip("GFPIC", 1, GFPIC_IRQ_BASE, gfpic->base,
89 handle_level_irq);
90 if (!gc) {
91 pr_err("Failed to allocate chip structures!\n");
92 ret = -ENOMEM;
93 goto out_iounmap;
94 }
95
96 ct = gc->chip_types;
97 ct->regs.enable = GFPIC_REG_IRQ_ENABLE;
98 ct->regs.disable = GFPIC_REG_IRQ_DISABLE;
99 ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
100 ct->chip.irq_mask = irq_gc_mask_disable_reg;
101
102 irq_setup_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS), 0,
103 IRQ_NOPROBE | IRQ_LEVEL, 0);
104
105 gfpic->irq_domain = irq_domain_add_legacy(of_node, GFPIC_NR_IRQS,
106 GFPIC_IRQ_BASE, 0,
107 &goldfish_irq_domain_ops,
108 NULL);
109 if (!gfpic->irq_domain) {
110 pr_err("Failed to add irqdomain!\n");
111 ret = -ENOMEM;
112 goto out_destroy_generic_chip;
113 }
114
115 irq_set_chained_handler_and_data(parent_irq,
116 goldfish_pic_cascade, gfpic);
117
118 pr_info("Successfully registered.\n");
119 return 0;
120
121out_destroy_generic_chip:
122 irq_destroy_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS),
123 IRQ_NOPROBE | IRQ_LEVEL, 0);
124out_iounmap:
125 iounmap(gfpic->base);
126out_unmap_irq:
127 irq_dispose_mapping(parent_irq);
128out_free:
129 kfree(gfpic);
130out_err:
131 pr_err("Failed to initialize! (errno = %d)\n", ret);
132 return ret;
133}
134
135IRQCHIP_DECLARE(google_gf_pic, "google,goldfish-pic", goldfish_pic_of_init);
136
