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5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/interrupt.h>
9#include <linux/irq.h>
10#include <linux/irqchip.h>
11#include <linux/irqchip/chained_irq.h>
12#include <linux/irqdomain.h>
13#include <linux/of_address.h>
14#include <linux/of_irq.h>
15
16#define IDT_PIC_NR_IRQS 32
17
18#define IDT_PIC_IRQ_PEND 0x00
19#define IDT_PIC_IRQ_MASK 0x08
20
21struct idt_pic_data {
22 void __iomem *base;
23 struct irq_domain *irq_domain;
24 struct irq_chip_generic *gc;
25};
26
27static void idt_irq_dispatch(struct irq_desc *desc)
28{
29 struct idt_pic_data *idtpic = irq_desc_get_handler_data(desc);
30 struct irq_chip *host_chip = irq_desc_get_chip(desc);
31 u32 pending, hwirq;
32
33 chained_irq_enter(host_chip, desc);
34
35 pending = irq_reg_readl(idtpic->gc, IDT_PIC_IRQ_PEND);
36 pending &= ~idtpic->gc->mask_cache;
37 while (pending) {
38 hwirq = __fls(pending);
39 generic_handle_domain_irq(idtpic->irq_domain, hwirq);
40 pending &= ~(1 << hwirq);
41 }
42
43 chained_irq_exit(host_chip, desc);
44}
45
46static int idt_pic_init(struct device_node *of_node, struct device_node *parent)
47{
48 struct irq_domain *domain;
49 struct idt_pic_data *idtpic;
50 struct irq_chip_generic *gc;
51 struct irq_chip_type *ct;
52 unsigned int parent_irq;
53 int ret = 0;
54
55 idtpic = kzalloc(sizeof(*idtpic), GFP_KERNEL);
56 if (!idtpic) {
57 ret = -ENOMEM;
58 goto out_err;
59 }
60
61 parent_irq = irq_of_parse_and_map(of_node, 0);
62 if (!parent_irq) {
63 pr_err("Failed to map parent IRQ!\n");
64 ret = -EINVAL;
65 goto out_free;
66 }
67
68 idtpic->base = of_iomap(of_node, 0);
69 if (!idtpic->base) {
70 pr_err("Failed to map base address!\n");
71 ret = -ENOMEM;
72 goto out_unmap_irq;
73 }
74
75 domain = irq_domain_add_linear(of_node, IDT_PIC_NR_IRQS,
76 &irq_generic_chip_ops, NULL);
77 if (!domain) {
78 pr_err("Failed to add irqdomain!\n");
79 ret = -ENOMEM;
80 goto out_iounmap;
81 }
82 idtpic->irq_domain = domain;
83
84 ret = irq_alloc_domain_generic_chips(domain, 32, 1, "IDTPIC",
85 handle_level_irq, 0,
86 IRQ_NOPROBE | IRQ_LEVEL, 0);
87 if (ret)
88 goto out_domain_remove;
89
90 gc = irq_get_domain_generic_chip(domain, 0);
91 gc->reg_base = idtpic->base;
92 gc->private = idtpic;
93
94 ct = gc->chip_types;
95 ct->regs.mask = IDT_PIC_IRQ_MASK;
96 ct->chip.irq_mask = irq_gc_mask_set_bit;
97 ct->chip.irq_unmask = irq_gc_mask_clr_bit;
98 idtpic->gc = gc;
99
100
101 writel(0xffffffff, idtpic->base + IDT_PIC_IRQ_MASK);
102 gc->mask_cache = 0xffffffff;
103
104 irq_set_chained_handler_and_data(parent_irq,
105 idt_irq_dispatch, idtpic);
106
107 return 0;
108
109out_domain_remove:
110 irq_domain_remove(domain);
111out_iounmap:
112 iounmap(idtpic->base);
113out_unmap_irq:
114 irq_dispose_mapping(parent_irq);
115out_free:
116 kfree(idtpic);
117out_err:
118 pr_err("Failed to initialize! (errno = %d)\n", ret);
119 return ret;
120}
121
122IRQCHIP_DECLARE(idt_pic, "idt,32434-pic", idt_pic_init);
123
