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
16 enum acpi_irq_model_id acpi_irq_model;
17
18 static struct fwnode_handle *acpi_gsi_domain_id;
19
acpi_gsi_get_irq_type(int trigger,int polarity)20 static 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 */
acpi_gsi_to_irq(u32 gsi,unsigned int * irq)49 int 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 }
61 EXPORT_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 */
acpi_register_gsi(struct device * dev,u32 gsi,int trigger,int polarity)73 int 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 }
90 EXPORT_SYMBOL_GPL(acpi_register_gsi);
91
92 /**
93 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
94 * @gsi: GSI IRQ number
95 */
acpi_unregister_gsi(u32 gsi)96 void 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 }
104 EXPORT_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 */
acpi_set_irq_model(enum acpi_irq_model_id model,struct fwnode_handle * fwnode)112 void __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