diff options
Diffstat (limited to 'drivers/acpi/gsi.c')
-rw-r--r-- | drivers/acpi/gsi.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/acpi/gsi.c b/drivers/acpi/gsi.c new file mode 100644 index 000000000000..38208f2d0e69 --- /dev/null +++ b/drivers/acpi/gsi.c | |||
@@ -0,0 +1,105 @@ | |||
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); | ||