Commit | Line | Data |
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d8f4f161 LP |
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 | ||
15 | enum acpi_irq_model_id acpi_irq_model; | |
16 | ||
17 | static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity) | |
18 | { | |
19 | switch (polarity) { | |
20 | case ACPI_ACTIVE_LOW: | |
21 | return trigger == ACPI_EDGE_SENSITIVE ? | |
22 | IRQ_TYPE_EDGE_FALLING : | |
23 | IRQ_TYPE_LEVEL_LOW; | |
24 | case ACPI_ACTIVE_HIGH: | |
25 | return trigger == ACPI_EDGE_SENSITIVE ? | |
26 | IRQ_TYPE_EDGE_RISING : | |
27 | IRQ_TYPE_LEVEL_HIGH; | |
28 | case ACPI_ACTIVE_BOTH: | |
29 | if (trigger == ACPI_EDGE_SENSITIVE) | |
30 | return IRQ_TYPE_EDGE_BOTH; | |
31 | default: | |
32 | return IRQ_TYPE_NONE; | |
33 | } | |
34 | } | |
35 | ||
36 | /** | |
37 | * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI | |
38 | * @gsi: GSI IRQ number to map | |
39 | * @irq: pointer where linux IRQ number is stored | |
40 | * | |
41 | * irq location updated with irq value [>0 on success, 0 on failure] | |
42 | * | |
43 | * Returns: linux IRQ number on success (>0) | |
44 | * -EINVAL on failure | |
45 | */ | |
46 | int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) | |
47 | { | |
48 | /* | |
49 | * Only default domain is supported at present, always find | |
50 | * the mapping corresponding to default domain by passing NULL | |
51 | * as irq_domain parameter | |
52 | */ | |
53 | *irq = irq_find_mapping(NULL, gsi); | |
54 | /* | |
55 | * *irq == 0 means no mapping, that should | |
56 | * be reported as a failure | |
57 | */ | |
58 | return (*irq > 0) ? *irq : -EINVAL; | |
59 | } | |
60 | EXPORT_SYMBOL_GPL(acpi_gsi_to_irq); | |
61 | ||
62 | /** | |
63 | * acpi_register_gsi() - Map a GSI to a linux IRQ number | |
64 | * @dev: device for which IRQ has to be mapped | |
65 | * @gsi: GSI IRQ number | |
66 | * @trigger: trigger type of the GSI number to be mapped | |
67 | * @polarity: polarity of the GSI to be mapped | |
68 | * | |
69 | * Returns: a valid linux IRQ number on success | |
70 | * -EINVAL on failure | |
71 | */ | |
72 | int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, | |
73 | int polarity) | |
74 | { | |
75 | unsigned int irq; | |
76 | unsigned int irq_type = acpi_gsi_get_irq_type(trigger, polarity); | |
77 | ||
78 | /* | |
79 | * There is no way at present to look-up the IRQ domain on ACPI, | |
80 | * hence always create mapping referring to the default domain | |
81 | * by passing NULL as irq_domain parameter | |
82 | */ | |
83 | irq = irq_create_mapping(NULL, gsi); | |
84 | if (!irq) | |
85 | return -EINVAL; | |
86 | ||
87 | /* Set irq type if specified and different than the current one */ | |
88 | if (irq_type != IRQ_TYPE_NONE && | |
89 | irq_type != irq_get_trigger_type(irq)) | |
90 | irq_set_irq_type(irq, irq_type); | |
91 | return irq; | |
92 | } | |
93 | EXPORT_SYMBOL_GPL(acpi_register_gsi); | |
94 | ||
95 | /** | |
96 | * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping | |
97 | * @gsi: GSI IRQ number | |
98 | */ | |
99 | void acpi_unregister_gsi(u32 gsi) | |
100 | { | |
101 | int irq = irq_find_mapping(NULL, gsi); | |
102 | ||
103 | irq_dispose_mapping(irq); | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(acpi_unregister_gsi); |