1 /*
2 * IRQ domain support for SH INTC subsystem
3 *
4 * Copyright (C) 2012 Paul Mundt
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10 #define pr_fmt(fmt) "intc: " fmt
11
12 #include <linux/irqdomain.h>
13 #include <linux/sh_intc.h>
14 #include <linux/export.h>
15 #include "internals.h"
16
17 /**
18 * intc_irq_domain_evt_xlate() - Generic xlate for vectored IRQs.
19 *
20 * This takes care of exception vector to hwirq translation through
21 * by way of evt2irq() translation.
22 *
23 * Note: For platforms that use a flat vector space without INTEVT this
24 * basically just mimics irq_domain_xlate_onecell() by way of a nopped
25 * out evt2irq() implementation.
26 */
27 static int intc_evt_xlate(struct irq_domain *d, struct device_node *ctrlr,
28 const u32 *intspec, unsigned int intsize,
29 unsigned long *out_hwirq, unsigned int *out_type)
30 {
31 if (WARN_ON(intsize < 1))
32 return -EINVAL;
33
34 *out_hwirq = evt2irq(intspec[0]);
35 *out_type = IRQ_TYPE_NONE;
36
37 return 0;
38 }
39
40 static const struct irq_domain_ops intc_evt_ops = {
41 .xlate = intc_evt_xlate,
42 };
43
44 void __init intc_irq_domain_init(struct intc_desc_int *d,
45 struct intc_hw_desc *hw)
46 {
47 unsigned int irq_base, irq_end;
48
49 /*
50 * Quick linear revmap check
51 */
52 irq_base = evt2irq(hw->vectors[0].vect);
53 irq_end = evt2irq(hw->vectors[hw->nr_vectors - 1].vect);
54
55 /*
56 * Linear domains have a hard-wired assertion that IRQs start at
57 * 0 in order to make some performance optimizations. Lamely
58 * restrict the linear case to these conditions here, taking the
59 * tree penalty for linear cases with non-zero hwirq bases.
60 */
61 if (irq_base == 0 && irq_end == (irq_base + hw->nr_vectors - 1))
62 d->domain = irq_domain_add_linear(NULL, hw->nr_vectors,
63 &intc_evt_ops, NULL);
64 else
65 d->domain = irq_domain_add_tree(NULL, &intc_evt_ops, NULL);
66
67 BUG_ON(!d->domain);
68 }