Agustin Vega-Frias | d44fa3d | 2017-02-02 18:23:58 -0500 | [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 | #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 | * |
Mark Salter | 1dc482b | 2017-07-11 12:45:43 -0400 | [diff] [blame] | 27 | * Returns: 0 on success |
Agustin Vega-Frias | d44fa3d | 2017-02-02 18:23:58 -0500 | [diff] [blame] | 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 | */ |
Mark Salter | 1dc482b | 2017-07-11 12:45:43 -0400 | [diff] [blame] | 40 | return (*irq > 0) ? 0 : -EINVAL; |
Agustin Vega-Frias | d44fa3d | 2017-02-02 18:23:58 -0500 | [diff] [blame] | 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_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source. |
| 89 | * @source: acpi_resource_source to use for the lookup. |
| 90 | * |
| 91 | * Description: |
| 92 | * Retrieve the fwhandle of the device referenced by the given IRQ resource |
| 93 | * source. |
| 94 | * |
| 95 | * Return: |
| 96 | * The referenced device fwhandle or NULL on failure |
| 97 | */ |
| 98 | static struct fwnode_handle * |
| 99 | acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source) |
| 100 | { |
| 101 | struct fwnode_handle *result; |
| 102 | struct acpi_device *device; |
| 103 | acpi_handle handle; |
| 104 | acpi_status status; |
| 105 | |
| 106 | if (!source->string_length) |
| 107 | return acpi_gsi_domain_id; |
| 108 | |
| 109 | status = acpi_get_handle(NULL, source->string_ptr, &handle); |
| 110 | if (WARN_ON(ACPI_FAILURE(status))) |
| 111 | return NULL; |
| 112 | |
| 113 | device = acpi_bus_get_acpi_device(handle); |
| 114 | if (WARN_ON(!device)) |
| 115 | return NULL; |
| 116 | |
| 117 | result = &device->fwnode; |
| 118 | acpi_bus_put_acpi_device(device); |
| 119 | return result; |
| 120 | } |
| 121 | |
| 122 | /* |
| 123 | * Context for the resource walk used to lookup IRQ resources. |
| 124 | * Contains a return code, the lookup index, and references to the flags |
| 125 | * and fwspec where the result is returned. |
| 126 | */ |
| 127 | struct acpi_irq_parse_one_ctx { |
| 128 | int rc; |
| 129 | unsigned int index; |
| 130 | unsigned long *res_flags; |
| 131 | struct irq_fwspec *fwspec; |
| 132 | }; |
| 133 | |
| 134 | /** |
| 135 | * acpi_irq_parse_one_match - Handle a matching IRQ resource. |
| 136 | * @fwnode: matching fwnode |
| 137 | * @hwirq: hardware IRQ number |
| 138 | * @triggering: triggering attributes of hwirq |
| 139 | * @polarity: polarity attributes of hwirq |
| 140 | * @polarity: polarity attributes of hwirq |
| 141 | * @shareable: shareable attributes of hwirq |
| 142 | * @ctx: acpi_irq_parse_one_ctx updated by this function |
| 143 | * |
| 144 | * Description: |
| 145 | * Handle a matching IRQ resource by populating the given ctx with |
| 146 | * the information passed. |
| 147 | */ |
| 148 | static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode, |
| 149 | u32 hwirq, u8 triggering, |
| 150 | u8 polarity, u8 shareable, |
| 151 | struct acpi_irq_parse_one_ctx *ctx) |
| 152 | { |
| 153 | if (!fwnode) |
| 154 | return; |
| 155 | ctx->rc = 0; |
| 156 | *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable); |
| 157 | ctx->fwspec->fwnode = fwnode; |
| 158 | ctx->fwspec->param[0] = hwirq; |
| 159 | ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity); |
| 160 | ctx->fwspec->param_count = 2; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * acpi_irq_parse_one_cb - Handle the given resource. |
| 165 | * @ares: resource to handle |
| 166 | * @context: context for the walk |
| 167 | * |
| 168 | * Description: |
| 169 | * This is called by acpi_walk_resources passing each resource returned by |
| 170 | * the _CRS method. We only inspect IRQ resources. Since IRQ resources |
| 171 | * might contain multiple interrupts we check if the index is within this |
| 172 | * one's interrupt array, otherwise we subtract the current resource IRQ |
| 173 | * count from the lookup index to prepare for the next resource. |
| 174 | * Once a match is found we call acpi_irq_parse_one_match to populate |
| 175 | * the result and end the walk by returning AE_CTRL_TERMINATE. |
| 176 | * |
| 177 | * Return: |
| 178 | * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching |
| 179 | * IRQ resource was found. |
| 180 | */ |
| 181 | static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares, |
| 182 | void *context) |
| 183 | { |
| 184 | struct acpi_irq_parse_one_ctx *ctx = context; |
| 185 | struct acpi_resource_irq *irq; |
| 186 | struct acpi_resource_extended_irq *eirq; |
| 187 | struct fwnode_handle *fwnode; |
| 188 | |
| 189 | switch (ares->type) { |
| 190 | case ACPI_RESOURCE_TYPE_IRQ: |
| 191 | irq = &ares->data.irq; |
| 192 | if (ctx->index >= irq->interrupt_count) { |
| 193 | ctx->index -= irq->interrupt_count; |
| 194 | return AE_OK; |
| 195 | } |
| 196 | fwnode = acpi_gsi_domain_id; |
| 197 | acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index], |
| 198 | irq->triggering, irq->polarity, |
| 199 | irq->sharable, ctx); |
| 200 | return AE_CTRL_TERMINATE; |
| 201 | case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: |
| 202 | eirq = &ares->data.extended_irq; |
| 203 | if (eirq->producer_consumer == ACPI_PRODUCER) |
| 204 | return AE_OK; |
| 205 | if (ctx->index >= eirq->interrupt_count) { |
| 206 | ctx->index -= eirq->interrupt_count; |
| 207 | return AE_OK; |
| 208 | } |
| 209 | fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source); |
| 210 | acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index], |
| 211 | eirq->triggering, eirq->polarity, |
| 212 | eirq->sharable, ctx); |
| 213 | return AE_CTRL_TERMINATE; |
| 214 | } |
| 215 | |
| 216 | return AE_OK; |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * acpi_irq_parse_one - Resolve an interrupt for a device |
| 221 | * @handle: the device whose interrupt is to be resolved |
| 222 | * @index: index of the interrupt to resolve |
| 223 | * @fwspec: structure irq_fwspec filled by this function |
| 224 | * @flags: resource flags filled by this function |
| 225 | * |
| 226 | * Description: |
| 227 | * Resolves an interrupt for a device by walking its CRS resources to find |
| 228 | * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec |
| 229 | * and flags. |
| 230 | * |
| 231 | * Return: |
| 232 | * The result stored in ctx.rc by the callback, or the default -EINVAL value |
| 233 | * if an error occurs. |
| 234 | */ |
| 235 | static int acpi_irq_parse_one(acpi_handle handle, unsigned int index, |
| 236 | struct irq_fwspec *fwspec, unsigned long *flags) |
| 237 | { |
| 238 | struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec }; |
| 239 | |
| 240 | acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx); |
| 241 | return ctx.rc; |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource. |
| 246 | * @handle: ACPI device handle |
| 247 | * @index: ACPI IRQ resource index to lookup |
| 248 | * @res: Linux IRQ resource to initialize |
| 249 | * |
| 250 | * Description: |
| 251 | * Look for the ACPI IRQ resource with the given index and use it to initialize |
| 252 | * the given Linux IRQ resource. |
| 253 | * |
| 254 | * Return: |
| 255 | * 0 on success |
| 256 | * -EINVAL if an error occurs |
| 257 | * -EPROBE_DEFER if the IRQ lookup/conversion failed |
| 258 | */ |
| 259 | int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res) |
| 260 | { |
| 261 | struct irq_fwspec fwspec; |
| 262 | struct irq_domain *domain; |
| 263 | unsigned long flags; |
| 264 | int rc; |
| 265 | |
| 266 | rc = acpi_irq_parse_one(handle, index, &fwspec, &flags); |
| 267 | if (rc) |
| 268 | return rc; |
| 269 | |
| 270 | domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY); |
| 271 | if (!domain) |
| 272 | return -EPROBE_DEFER; |
| 273 | |
| 274 | rc = irq_create_fwspec_mapping(&fwspec); |
| 275 | if (rc <= 0) |
| 276 | return -EINVAL; |
| 277 | |
| 278 | res->start = rc; |
| 279 | res->end = rc; |
| 280 | res->flags = flags; |
| 281 | |
| 282 | return 0; |
| 283 | } |
| 284 | EXPORT_SYMBOL_GPL(acpi_irq_get); |
| 285 | |
| 286 | /** |
| 287 | * acpi_set_irq_model - Setup the GSI irqdomain information |
| 288 | * @model: the value assigned to acpi_irq_model |
| 289 | * @fwnode: the irq_domain identifier for mapping and looking up |
| 290 | * GSI interrupts |
| 291 | */ |
| 292 | void __init acpi_set_irq_model(enum acpi_irq_model_id model, |
| 293 | struct fwnode_handle *fwnode) |
| 294 | { |
| 295 | acpi_irq_model = model; |
| 296 | acpi_gsi_domain_id = fwnode; |
| 297 | } |