1/*
 2 * ACPI GSI IRQ layer
 3 *
 4 * Copyright (C) 2015 ARM Ltd.
 5 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
 6 *
 7 * This program is free software; you can redistribute it and/or modify
 8 * it under the terms of the GNU General Public License version 2 as
 9 * published by the Free Software Foundation.
10 */
11#include <linux/acpi.h>
12#include <linux/irq.h>
13#include <linux/irqdomain.h>
14#include <linux/of.h>
15
16enum acpi_irq_model_id acpi_irq_model;
17
18static struct fwnode_handle *acpi_gsi_domain_id;
19
20/**
21 * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
22 * @gsi: GSI IRQ number to map
23 * @irq: pointer where linux IRQ number is stored
24 *
25 * irq location updated with irq value [>0 on success, 0 on failure]
26 *
27 * Returns: linux IRQ number on success (>0)
28 *          -EINVAL on failure
29 */
30int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
31{
32	struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
33							DOMAIN_BUS_ANY);
34
35	*irq = irq_find_mapping(d, gsi);
36	/*
37	 * *irq == 0 means no mapping, that should
38	 * be reported as a failure
39	 */
40	return (*irq > 0) ? *irq : -EINVAL;
41}
42EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
43
44/**
45 * acpi_register_gsi() - Map a GSI to a linux IRQ number
46 * @dev: device for which IRQ has to be mapped
47 * @gsi: GSI IRQ number
48 * @trigger: trigger type of the GSI number to be mapped
49 * @polarity: polarity of the GSI to be mapped
50 *
51 * Returns: a valid linux IRQ number on success
52 *          -EINVAL on failure
53 */
54int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
55		      int polarity)
56{
57	struct irq_fwspec fwspec;
58
59	if (WARN_ON(!acpi_gsi_domain_id)) {
60		pr_warn("GSI: No registered irqchip, giving up\n");
61		return -EINVAL;
62	}
63
64	fwspec.fwnode = acpi_gsi_domain_id;
65	fwspec.param[0] = gsi;
66	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
67	fwspec.param_count = 2;
68
69	return irq_create_fwspec_mapping(&fwspec);
70}
71EXPORT_SYMBOL_GPL(acpi_register_gsi);
72
73/**
74 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
75 * @gsi: GSI IRQ number
76 */
77void acpi_unregister_gsi(u32 gsi)
78{
79	struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
80							DOMAIN_BUS_ANY);
81	int irq = irq_find_mapping(d, gsi);
82
83	irq_dispose_mapping(irq);
84}
85EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
86
87/**
88 * acpi_set_irq_model - Setup the GSI irqdomain information
89 * @model: the value assigned to acpi_irq_model
90 * @fwnode: the irq_domain identifier for mapping and looking up
91 *          GSI interrupts
92 */
93void __init acpi_set_irq_model(enum acpi_irq_model_id model,
94			       struct fwnode_handle *fwnode)
95{
96	acpi_irq_model = model;
97	acpi_gsi_domain_id = fwnode;
98}