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 /**
  21  * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
  22  * @gsi: GSI IRQ number to map
  23  * @irq: pointer where linux IRQ number is stored
  24  *
  25  * irq location updated with irq value [>0 on success, 0 on failure]
  26  *
  27  * Returns: linux IRQ number on success (>0)
  28  *          -EINVAL on failure
  29  */
  30 int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
  31 {
  32         struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
  33                                                         DOMAIN_BUS_ANY);
  34
  35         *irq = irq_find_mapping(d, gsi);
  36         /*
  37          * *irq == 0 means no mapping, that should
  38          * be reported as a failure
  39          */
  40         return (*irq > 0) ? *irq : -EINVAL;
  41 }
  42 EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
  43
  44 /**
  45  * acpi_register_gsi() - Map a GSI to a linux IRQ number
  46  * @dev: device for which IRQ has to be mapped
  47  * @gsi: GSI IRQ number
  48  * @trigger: trigger type of the GSI number to be mapped
  49  * @polarity: polarity of the GSI to be mapped
  50  *
  51  * Returns: a valid linux IRQ number on success
  52  *          -EINVAL on failure
  53  */
  54 int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
  55                       int polarity)
  56 {
  57         struct irq_fwspec fwspec;
  58
  59         if (WARN_ON(!acpi_gsi_domain_id)) {
  60                 pr_warn("GSI: No registered irqchip, giving up\n");
  61                 return -EINVAL;
  62         }
  63
  64         fwspec.fwnode = acpi_gsi_domain_id;
  65         fwspec.param[0] = gsi;
  66         fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
  67         fwspec.param_count = 2;
  68
  69         return irq_create_fwspec_mapping(&fwspec);
  70 }
  71 EXPORT_SYMBOL_GPL(acpi_register_gsi);
  72
  73 /**
  74  * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
  75  * @gsi: GSI IRQ number
  76  */
  77 void acpi_unregister_gsi(u32 gsi)
  78 {
  79         struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
  80                                                         DOMAIN_BUS_ANY);
  81         int irq = irq_find_mapping(d, gsi);
  82
  83         irq_dispose_mapping(irq);
  84 }
  85 EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
  86
  87 /**
  88  * acpi_set_irq_model - Setup the GSI irqdomain information
  89  * @model: the value assigned to acpi_irq_model
  90  * @fwnode: the irq_domain identifier for mapping and looking up
  91  *          GSI interrupts
  92  */
  93 void __init acpi_set_irq_model(enum acpi_irq_model_id model,
  94                                struct fwnode_handle *fwnode)
  95 {
  96         acpi_irq_model = model;
  97         acpi_gsi_domain_id = fwnode;
  98 }