1 /*
2  * Xtensa built-in interrupt controller
3  *
4  * Copyright (C) 2002 - 2013 Tensilica, Inc.
5  * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
6  *
7  * This file is subject to the terms and conditions of the GNU General Public
8  * License.  See the file "COPYING" in the main directory of this archive
9  * for more details.
10  *
11  * Chris Zankel <chris@zankel.net>
12  * Kevin Chea
13  */
14 
15 #include <linux/interrupt.h>
16 #include <linux/irqdomain.h>
17 #include <linux/irq.h>
18 #include <linux/irqchip.h>
19 #include <linux/of.h>
20 
21 unsigned int cached_irq_mask;
22 
23 /*
24  * Device Tree IRQ specifier translation function which works with one or
25  * two cell bindings. First cell value maps directly to the hwirq number.
26  * Second cell if present specifies whether hwirq number is external (1) or
27  * internal (0).
28  */
29 static int xtensa_pic_irq_domain_xlate(struct irq_domain *d,
30 		struct device_node *ctrlr,
31 		const u32 *intspec, unsigned int intsize,
32 		unsigned long *out_hwirq, unsigned int *out_type)
33 {
34 	return xtensa_irq_domain_xlate(intspec, intsize,
35 			intspec[0], intspec[0],
36 			out_hwirq, out_type);
37 }
38 
39 static const struct irq_domain_ops xtensa_irq_domain_ops = {
40 	.xlate = xtensa_pic_irq_domain_xlate,
41 	.map = xtensa_irq_map,
42 };
43 
44 static void xtensa_irq_mask(struct irq_data *d)
45 {
46 	cached_irq_mask &= ~(1 << d->hwirq);
47 	set_sr(cached_irq_mask, intenable);
48 }
49 
50 static void xtensa_irq_unmask(struct irq_data *d)
51 {
52 	cached_irq_mask |= 1 << d->hwirq;
53 	set_sr(cached_irq_mask, intenable);
54 }
55 
56 static void xtensa_irq_enable(struct irq_data *d)
57 {
58 	xtensa_irq_unmask(d);
59 }
60 
61 static void xtensa_irq_disable(struct irq_data *d)
62 {
63 	xtensa_irq_mask(d);
64 }
65 
66 static void xtensa_irq_ack(struct irq_data *d)
67 {
68 	set_sr(1 << d->hwirq, intclear);
69 }
70 
71 static int xtensa_irq_retrigger(struct irq_data *d)
72 {
73 	set_sr(1 << d->hwirq, intset);
74 	return 1;
75 }
76 
77 static struct irq_chip xtensa_irq_chip = {
78 	.name		= "xtensa",
79 	.irq_enable	= xtensa_irq_enable,
80 	.irq_disable	= xtensa_irq_disable,
81 	.irq_mask	= xtensa_irq_mask,
82 	.irq_unmask	= xtensa_irq_unmask,
83 	.irq_ack	= xtensa_irq_ack,
84 	.irq_retrigger	= xtensa_irq_retrigger,
85 };
86 
87 int __init xtensa_pic_init_legacy(struct device_node *interrupt_parent)
88 {
89 	struct irq_domain *root_domain =
90 		irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0,
91 				&xtensa_irq_domain_ops, &xtensa_irq_chip);
92 	irq_set_default_host(root_domain);
93 	return 0;
94 }
95 
96 static int __init xtensa_pic_init(struct device_node *np,
97 		struct device_node *interrupt_parent)
98 {
99 	struct irq_domain *root_domain =
100 		irq_domain_add_linear(np, NR_IRQS, &xtensa_irq_domain_ops,
101 				&xtensa_irq_chip);
102 	irq_set_default_host(root_domain);
103 	return 0;
104 }
105 IRQCHIP_DECLARE(xtensa_irq_chip, "cdns,xtensa-pic", xtensa_pic_init);
106