1/*
2 * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <linux/device.h>
19#include <linux/msi.h>
20#include <linux/of.h>
21#include <linux/of_irq.h>
22
23static struct irq_chip its_pmsi_irq_chip = {
24	.name			= "ITS-pMSI",
25};
26
27static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
28			    int nvec, msi_alloc_info_t *info)
29{
30	struct msi_domain_info *msi_info;
31	u32 dev_id;
32	int ret, index = 0;
33
34	msi_info = msi_get_domain_info(domain->parent);
35
36	/* Suck the DeviceID out of the msi-parent property */
37	do {
38		struct of_phandle_args args;
39
40		ret = of_parse_phandle_with_args(dev->of_node,
41						 "msi-parent", "#msi-cells",
42						 index, &args);
43		if (args.np == irq_domain_get_of_node(domain)) {
44			if (WARN_ON(args.args_count != 1))
45				return -EINVAL;
46			dev_id = args.args[0];
47			break;
48		}
49	} while (!ret);
50
51	if (ret)
52		return ret;
53
54	/* ITS specific DeviceID, as the core ITS ignores dev. */
55	info->scratchpad[0].ul = dev_id;
56
57	return msi_info->ops->msi_prepare(domain->parent,
58					  dev, nvec, info);
59}
60
61static struct msi_domain_ops its_pmsi_ops = {
62	.msi_prepare	= its_pmsi_prepare,
63};
64
65static struct msi_domain_info its_pmsi_domain_info = {
66	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
67	.ops	= &its_pmsi_ops,
68	.chip	= &its_pmsi_irq_chip,
69};
70
71static struct of_device_id its_device_id[] = {
72	{	.compatible	= "arm,gic-v3-its",	},
73	{},
74};
75
76static int __init its_pmsi_init(void)
77{
78	struct device_node *np;
79	struct irq_domain *parent;
80
81	for (np = of_find_matching_node(NULL, its_device_id); np;
82	     np = of_find_matching_node(np, its_device_id)) {
83		if (!of_property_read_bool(np, "msi-controller"))
84			continue;
85
86		parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
87		if (!parent || !msi_get_domain_info(parent)) {
88			pr_err("%s: unable to locate ITS domain\n",
89			       np->full_name);
90			continue;
91		}
92
93		if (!platform_msi_create_irq_domain(of_node_to_fwnode(np),
94						    &its_pmsi_domain_info,
95						    parent)) {
96			pr_err("%s: unable to create platform domain\n",
97			       np->full_name);
98			continue;
99		}
100
101		pr_info("Platform MSI: %s domain created\n", np->full_name);
102	}
103
104	return 0;
105}
106early_initcall(its_pmsi_init);
107