| Lorenzo Pieralisi | d8f4f16 | 2015-03-24 17:58:51 +0000 | [diff] [blame] | 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); |