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