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
20static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity)
21{
22	switch (polarity) {
23	case ACPI_ACTIVE_LOW:
24		return trigger == ACPI_EDGE_SENSITIVE ?
25		       IRQ_TYPE_EDGE_FALLING :
26		       IRQ_TYPE_LEVEL_LOW;
27	case ACPI_ACTIVE_HIGH:
28		return trigger == ACPI_EDGE_SENSITIVE ?
29		       IRQ_TYPE_EDGE_RISING :
30		       IRQ_TYPE_LEVEL_HIGH;
31	case ACPI_ACTIVE_BOTH:
32		if (trigger == ACPI_EDGE_SENSITIVE)
33			return IRQ_TYPE_EDGE_BOTH;
34	default:
35		return IRQ_TYPE_NONE;
36	}
37}
38
39/**
40 * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
41 * @gsi: GSI IRQ number to map
42 * @irq: pointer where linux IRQ number is stored
43 *
44 * irq location updated with irq value [>0 on success, 0 on failure]
45 *
46 * Returns: linux IRQ number on success (>0)
47 *          -EINVAL on failure
48 */
49int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
50{
51	struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
52							DOMAIN_BUS_ANY);
53
54	*irq = irq_find_mapping(d, gsi);
55	/*
56	 * *irq == 0 means no mapping, that should
57	 * be reported as a failure
58	 */
59	return (*irq > 0) ? *irq : -EINVAL;
60}
61EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
62
63/**
64 * acpi_register_gsi() - Map a GSI to a linux IRQ number
65 * @dev: device for which IRQ has to be mapped
66 * @gsi: GSI IRQ number
67 * @trigger: trigger type of the GSI number to be mapped
68 * @polarity: polarity of the GSI to be mapped
69 *
70 * Returns: a valid linux IRQ number on success
71 *          -EINVAL on failure
72 */
73int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
74		      int polarity)
75{
76	struct irq_fwspec fwspec;
77
78	if (WARN_ON(!acpi_gsi_domain_id)) {
79		pr_warn("GSI: No registered irqchip, giving up\n");
80		return -EINVAL;
81	}
82
83	fwspec.fwnode = acpi_gsi_domain_id;
84	fwspec.param[0] = gsi;
85	fwspec.param[1] = acpi_gsi_get_irq_type(trigger, polarity);
86	fwspec.param_count = 2;
87
88	return irq_create_fwspec_mapping(&fwspec);
89}
90EXPORT_SYMBOL_GPL(acpi_register_gsi);
91
92/**
93 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
94 * @gsi: GSI IRQ number
95 */
96void acpi_unregister_gsi(u32 gsi)
97{
98	struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
99							DOMAIN_BUS_ANY);
100	int irq = irq_find_mapping(d, gsi);
101
102	irq_dispose_mapping(irq);
103}
104EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
105
106/**
107 * acpi_set_irq_model - Setup the GSI irqdomain information
108 * @model: the value assigned to acpi_irq_model
109 * @fwnode: the irq_domain identifier for mapping and looking up
110 *          GSI interrupts
111 */
112void __init acpi_set_irq_model(enum acpi_irq_model_id model,
113			       struct fwnode_handle *fwnode)
114{
115	acpi_irq_model = model;
116	acpi_gsi_domain_id = fwnode;
117}
118