drivers/acpi/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ACPI GSI IRQ layer
   4  *
   5  * Copyright (C) 2015 ARM Ltd.
   6  * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
   7  */
   8 #include <linux/acpi.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqdomain.h>
  11 #include <linux/of.h>
  12
  13 enum acpi_irq_model_id acpi_irq_model;
  14
  15 static struct fwnode_handle *acpi_gsi_domain_id;
  16
  17 /**
  18  * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
  19  * @gsi: GSI IRQ number to map
  20  * @irq: pointer where linux IRQ number is stored
  21  *
  22  * irq location updated with irq value [>0 on success, 0 on failure]
  23  *
  24  * Returns: 0 on success
  25  *          -EINVAL on failure
  26  */
  27 int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
  28 {
  29         struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
  30                                                         DOMAIN_BUS_ANY);
  31
  32         *irq = irq_find_mapping(d, gsi);
  33         /*
  34          * *irq == 0 means no mapping, that should
  35          * be reported as a failure
  36          */
  37         return (*irq > 0) ? 0 : -EINVAL;
  38 }
  39 EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
  40
  41 /**
  42  * acpi_register_gsi() - Map a GSI to a linux IRQ number
  43  * @dev: device for which IRQ has to be mapped
  44  * @gsi: GSI IRQ number
  45  * @trigger: trigger type of the GSI number to be mapped
  46  * @polarity: polarity of the GSI to be mapped
  47  *
  48  * Returns: a valid linux IRQ number on success
  49  *          -EINVAL on failure
  50  */
  51 int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
  52                       int polarity)
  53 {
  54         struct irq_fwspec fwspec;
  55
  56         if (WARN_ON(!acpi_gsi_domain_id)) {
  57                 pr_warn("GSI: No registered irqchip, giving up\n");
  58                 return -EINVAL;
  59         }
  60
  61         fwspec.fwnode = acpi_gsi_domain_id;
  62         fwspec.param[0] = gsi;
  63         fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
  64         fwspec.param_count = 2;
  65
  66         return irq_create_fwspec_mapping(&fwspec);
  67 }
  68 EXPORT_SYMBOL_GPL(acpi_register_gsi);
  69
  70 /**
  71  * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
  72  * @gsi: GSI IRQ number
  73  */
  74 void acpi_unregister_gsi(u32 gsi)
  75 {
  76         struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
  77                                                         DOMAIN_BUS_ANY);
  78         int irq = irq_find_mapping(d, gsi);
  79
  80         irq_dispose_mapping(irq);
  81 }
  82 EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
  83
  84 /**
  85  * acpi_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source.
  86  * @source: acpi_resource_source to use for the lookup.
  87  *
  88  * Description:
  89  * Retrieve the fwhandle of the device referenced by the given IRQ resource
  90  * source.
  91  *
  92  * Return:
  93  * The referenced device fwhandle or NULL on failure
  94  */
  95 static struct fwnode_handle *
  96 acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source)
  97 {
  98         struct fwnode_handle *result;
  99         struct acpi_device *device;
 100         acpi_handle handle;
 101         acpi_status status;
 102
 103         if (!source->string_length)
 104                 return acpi_gsi_domain_id;
 105
 106         status = acpi_get_handle(NULL, source->string_ptr, &handle);
 107         if (WARN_ON(ACPI_FAILURE(status)))
 108                 return NULL;
 109
 110         device = acpi_bus_get_acpi_device(handle);
 111         if (WARN_ON(!device))
 112                 return NULL;
 113
 114         result = &device->fwnode;
 115         acpi_bus_put_acpi_device(device);
 116         return result;
 117 }
 118
 119 /*
 120  * Context for the resource walk used to lookup IRQ resources.
 121  * Contains a return code, the lookup index, and references to the flags
 122  * and fwspec where the result is returned.
 123  */
 124 struct acpi_irq_parse_one_ctx {
 125         int rc;
 126         unsigned int index;
 127         unsigned long *res_flags;
 128         struct irq_fwspec *fwspec;
 129 };
 130
 131 /**
 132  * acpi_irq_parse_one_match - Handle a matching IRQ resource.
 133  * @fwnode: matching fwnode
 134  * @hwirq: hardware IRQ number
 135  * @triggering: triggering attributes of hwirq
 136  * @polarity: polarity attributes of hwirq
 137  * @polarity: polarity attributes of hwirq
 138  * @shareable: shareable attributes of hwirq
 139  * @ctx: acpi_irq_parse_one_ctx updated by this function
 140  *
 141  * Description:
 142  * Handle a matching IRQ resource by populating the given ctx with
 143  * the information passed.
 144  */
 145 static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
 146                                             u32 hwirq, u8 triggering,
 147                                             u8 polarity, u8 shareable,
 148                                             struct acpi_irq_parse_one_ctx *ctx)
 149 {
 150         if (!fwnode)
 151                 return;
 152         ctx->rc = 0;
 153         *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
 154         ctx->fwspec->fwnode = fwnode;
 155         ctx->fwspec->param[0] = hwirq;
 156         ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
 157         ctx->fwspec->param_count = 2;
 158 }
 159
 160 /**
 161  * acpi_irq_parse_one_cb - Handle the given resource.
 162  * @ares: resource to handle
 163  * @context: context for the walk
 164  *
 165  * Description:
 166  * This is called by acpi_walk_resources passing each resource returned by
 167  * the _CRS method. We only inspect IRQ resources. Since IRQ resources
 168  * might contain multiple interrupts we check if the index is within this
 169  * one's interrupt array, otherwise we subtract the current resource IRQ
 170  * count from the lookup index to prepare for the next resource.
 171  * Once a match is found we call acpi_irq_parse_one_match to populate
 172  * the result and end the walk by returning AE_CTRL_TERMINATE.
 173  *
 174  * Return:
 175  * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching
 176  * IRQ resource was found.
 177  */
 178 static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
 179                                          void *context)
 180 {
 181         struct acpi_irq_parse_one_ctx *ctx = context;
 182         struct acpi_resource_irq *irq;
 183         struct acpi_resource_extended_irq *eirq;
 184         struct fwnode_handle *fwnode;
 185
 186         switch (ares->type) {
 187         case ACPI_RESOURCE_TYPE_IRQ:
 188                 irq = &ares->data.irq;
 189                 if (ctx->index >= irq->interrupt_count) {
 190                         ctx->index -= irq->interrupt_count;
 191                         return AE_OK;
 192                 }
 193                 fwnode = acpi_gsi_domain_id;
 194                 acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
 195                                          irq->triggering, irq->polarity,
 196                                          irq->shareable, ctx);
 197                 return AE_CTRL_TERMINATE;
 198         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 199                 eirq = &ares->data.extended_irq;
 200                 if (eirq->producer_consumer == ACPI_PRODUCER)
 201                         return AE_OK;
 202                 if (ctx->index >= eirq->interrupt_count) {
 203                         ctx->index -= eirq->interrupt_count;
 204                         return AE_OK;
 205                 }
 206                 fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source);
 207                 acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
 208                                          eirq->triggering, eirq->polarity,
 209                                          eirq->shareable, ctx);
 210                 return AE_CTRL_TERMINATE;
 211         }
 212
 213         return AE_OK;
 214 }
 215
 216 /**
 217  * acpi_irq_parse_one - Resolve an interrupt for a device
 218  * @handle: the device whose interrupt is to be resolved
 219  * @index: index of the interrupt to resolve
 220  * @fwspec: structure irq_fwspec filled by this function
 221  * @flags: resource flags filled by this function
 222  *
 223  * Description:
 224  * Resolves an interrupt for a device by walking its CRS resources to find
 225  * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec
 226  * and flags.
 227  *
 228  * Return:
 229  * The result stored in ctx.rc by the callback, or the default -EINVAL value
 230  * if an error occurs.
 231  */
 232 static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,
 233                               struct irq_fwspec *fwspec, unsigned long *flags)
 234 {
 235         struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };
 236
 237         acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx);
 238         return ctx.rc;
 239 }
 240
 241 /**
 242  * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource.
 243  * @handle: ACPI device handle
 244  * @index:  ACPI IRQ resource index to lookup
 245  * @res:    Linux IRQ resource to initialize
 246  *
 247  * Description:
 248  * Look for the ACPI IRQ resource with the given index and use it to initialize
 249  * the given Linux IRQ resource.
 250  *
 251  * Return:
 252  * 0 on success
 253  * -EINVAL if an error occurs
 254  * -EPROBE_DEFER if the IRQ lookup/conversion failed
 255  */
 256 int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
 257 {
 258         struct irq_fwspec fwspec;
 259         struct irq_domain *domain;
 260         unsigned long flags;
 261         int rc;
 262
 263         rc = acpi_irq_parse_one(handle, index, &fwspec, &flags);
 264         if (rc)
 265                 return rc;
 266
 267         domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
 268         if (!domain)
 269                 return -EPROBE_DEFER;
 270
 271         rc = irq_create_fwspec_mapping(&fwspec);
 272         if (rc <= 0)
 273                 return -EINVAL;
 274
 275         res->start = rc;
 276         res->end = rc;
 277         res->flags = flags;
 278
 279         return 0;
 280 }
 281 EXPORT_SYMBOL_GPL(acpi_irq_get);
 282
 283 /**
 284  * acpi_set_irq_model - Setup the GSI irqdomain information
 285  * @model: the value assigned to acpi_irq_model
 286  * @fwnode: the irq_domain identifier for mapping and looking up
 287  *          GSI interrupts
 288  */
 289 void __init acpi_set_irq_model(enum acpi_irq_model_id model,
 290                                struct fwnode_handle *fwnode)
 291 {
 292         acpi_irq_model = model;
 293         acpi_gsi_domain_id = fwnode;
 294 }
 295
 296 /**
 297  * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default
 298  *                             GSI domain as its parent.
 299  * @flags:      Irq domain flags associated with the domain
 300  * @size:       Size of the domain.
 301  * @fwnode:     Optional fwnode of the interrupt controller
 302  * @ops:        Pointer to the interrupt domain callbacks
 303  * @host_data:  Controller private data pointer
 304  */
 305 struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
 306                                              unsigned int size,
 307                                              struct fwnode_handle *fwnode,
 308                                              const struct irq_domain_ops *ops,
 309                                              void *host_data)
 310 {
 311         struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
 312                                                         DOMAIN_BUS_ANY);
 313
 314         if (!d)
 315                 return NULL;
 316
 317         return irq_domain_create_hierarchy(d, flags, size, fwnode, ops,
 318                                            host_data);
 319 }
 320 EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy);