drivers/acpi/gsi.c

   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
  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  */
  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  */
  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  */
  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  */
 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 }