mcs814x: implement MULTI_IRQ_HANDLER
[openwrt/svn-archive/archive.git] / target / linux / mcs814x / files-3.3 / arch / arm / mach-mcs814x / irq.c
1 /*
2 * Moschip MCS814x generic interrupt controller routines
3 *
4 * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
5 *
6 * Licensed under the GPLv2
7 */
8 #include <linux/init.h>
9 #include <linux/irq.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <linux/irqdomain.h>
14
15 #include <asm/exception.h>
16 #include <asm/mach/irq.h>
17 #include <mach/mcs814x.h>
18
19 static void __iomem *mcs814x_intc_base;
20
21 static void __init mcs814x_alloc_gc(void __iomem *base, unsigned int irq_start,
22 unsigned int num)
23 {
24 struct irq_chip_generic *gc;
25 struct irq_chip_type *ct;
26
27 gc = irq_alloc_generic_chip("mcs814x-intc", 1,
28 irq_start, base, handle_level_irq);
29 if (!gc)
30 panic("unable to allocate generic irq chip");
31
32 ct = gc->chip_types;
33 ct->chip.irq_ack = irq_gc_unmask_enable_reg;
34 ct->chip.irq_mask = irq_gc_mask_clr_bit;
35 ct->chip.irq_unmask = irq_gc_mask_set_bit;
36 ct->regs.mask = MCS814X_IRQ_MASK;
37 ct->regs.enable = MCS814X_IRQ_ICR;
38
39 irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
40 IRQ_NOREQUEST, 0);
41
42 /* Clear all interrupts */
43 writel_relaxed(0xffffffff, base + MCS814X_IRQ_ICR);
44 }
45
46 asmlinkage void __exception_irq_entry mcs814x_handle_irq(struct pt_regs *regs)
47 {
48 u32 status, irq;
49
50 do {
51 /* read the status register */
52 status = __raw_readl(mcs814x_intc_base + MCS814X_IRQ_STS0);
53 if (!status)
54 break;
55
56 irq = ffs(status) - 1;
57 status |= (1 << irq);
58 /* clear the interrupt */
59 __raw_writel(status, mcs814x_intc_base + MCS814X_IRQ_STS0);
60 /* call the generic handler */
61 handle_IRQ(irq, regs);
62
63 } while (1);
64 }
65
66 static const struct of_device_id mcs814x_intc_ids[] = {
67 { .compatible = "moschip,mcs814x-intc" },
68 { /* sentinel */ },
69 };
70
71 void __init mcs814x_of_irq_init(void)
72 {
73 struct device_node *np;
74
75 np = of_find_matching_node(NULL, mcs814x_intc_ids);
76 if (!np)
77 panic("unable to find compatible intc node in dtb\n");
78
79 mcs814x_intc_base = of_iomap(np, 0);
80 if (!mcs814x_intc_base)
81 panic("unable to map intc cpu registers\n");
82
83 irq_domain_add_simple(np, 0);
84
85 of_node_put(np);
86
87 mcs814x_alloc_gc(mcs814x_intc_base, 0, 32);
88 }
89