xref: /openbmc/linux/arch/arm/plat-orion/irq.c (revision f6723b56)
1 /*
2  * arch/arm/plat-orion/irq.c
3  *
4  * Marvell Orion SoC IRQ handling.
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2.  This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/irq.h>
14 #include <linux/irqdomain.h>
15 #include <linux/io.h>
16 #include <linux/of_address.h>
17 #include <linux/of_irq.h>
18 #include <asm/exception.h>
19 #include <plat/irq.h>
20 #include <plat/orion-gpio.h>
21 #include <mach/bridge-regs.h>
22 
23 #ifdef CONFIG_MULTI_IRQ_HANDLER
24 /*
25  * Compiling with both non-DT and DT support enabled, will
26  * break asm irq handler used by non-DT boards. Therefore,
27  * we provide a C-style irq handler even for non-DT boards,
28  * if MULTI_IRQ_HANDLER is set.
29  *
30  * Notes:
31  * - this is prepared for Kirkwood and Dove only, update
32  *   accordingly if you add Orion5x or MV78x00.
33  * - Orion5x uses different macro names and has only one
34  *   set of CAUSE/MASK registers.
35  * - MV78x00 uses the same macro names but has a third
36  *   set of CAUSE/MASK registers.
37  *
38  */
39 
40 static void __iomem *orion_irq_base = IRQ_VIRT_BASE;
41 
42 asmlinkage void
43 __exception_irq_entry orion_legacy_handle_irq(struct pt_regs *regs)
44 {
45 	u32 stat;
46 
47 	stat = readl_relaxed(orion_irq_base + IRQ_CAUSE_LOW_OFF);
48 	stat &= readl_relaxed(orion_irq_base + IRQ_MASK_LOW_OFF);
49 	if (stat) {
50 		unsigned int hwirq = __fls(stat);
51 		handle_IRQ(hwirq, regs);
52 		return;
53 	}
54 	stat = readl_relaxed(orion_irq_base + IRQ_CAUSE_HIGH_OFF);
55 	stat &= readl_relaxed(orion_irq_base + IRQ_MASK_HIGH_OFF);
56 	if (stat) {
57 		unsigned int hwirq = 32 + __fls(stat);
58 		handle_IRQ(hwirq, regs);
59 		return;
60 	}
61 }
62 #endif
63 
64 void __init orion_irq_init(unsigned int irq_start, void __iomem *maskaddr)
65 {
66 	struct irq_chip_generic *gc;
67 	struct irq_chip_type *ct;
68 
69 	/*
70 	 * Mask all interrupts initially.
71 	 */
72 	writel(0, maskaddr);
73 
74 	gc = irq_alloc_generic_chip("orion_irq", 1, irq_start, maskaddr,
75 				    handle_level_irq);
76 	ct = gc->chip_types;
77 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
78 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
79 	irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_MASK_CACHE,
80 			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
81 
82 #ifdef CONFIG_MULTI_IRQ_HANDLER
83 	set_handle_irq(orion_legacy_handle_irq);
84 #endif
85 }
86 
87 #ifdef CONFIG_OF
88 static int __init orion_add_irq_domain(struct device_node *np,
89 				       struct device_node *interrupt_parent)
90 {
91 	int i = 0;
92 	void __iomem *base;
93 
94 	do {
95 		base = of_iomap(np, i);
96 		if (base) {
97 			orion_irq_init(i * 32, base + 0x04);
98 			i++;
99 		}
100 	} while (base);
101 
102 	irq_domain_add_legacy(np, i * 32, 0, 0,
103 			      &irq_domain_simple_ops, NULL);
104 	return 0;
105 }
106 
107 static const struct of_device_id orion_irq_match[] = {
108 	{ .compatible = "marvell,orion-intc",
109 	  .data = orion_add_irq_domain, },
110 	{},
111 };
112 
113 void __init orion_dt_init_irq(void)
114 {
115 	of_irq_init(orion_irq_match);
116 }
117 #endif
118