diff options
Diffstat (limited to 'drivers/acpi/irq.c')
| -rw-r--r-- | drivers/acpi/irq.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c new file mode 100644 index 000000000..1687483ff --- /dev/null +++ b/drivers/acpi/irq.c @@ -0,0 +1,356 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ACPI GSI IRQ layer + * + * Copyright (C) 2015 ARM Ltd. + * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> + */ +#include <linux/acpi.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/of.h> + +enum acpi_irq_model_id acpi_irq_model; + +static struct fwnode_handle *(*acpi_get_gsi_domain_id)(u32 gsi); +static u32 (*acpi_gsi_to_irq_fallback)(u32 gsi); + +/** + * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI + * @gsi: GSI IRQ number to map + * @irq: pointer where linux IRQ number is stored + * + * irq location updated with irq value [>0 on success, 0 on failure] + * + * Returns: 0 on success + * -EINVAL on failure + */ +int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) +{ + struct irq_domain *d; + + d = irq_find_matching_fwnode(acpi_get_gsi_domain_id(gsi), + DOMAIN_BUS_ANY); + *irq = irq_find_mapping(d, gsi); + /* + * *irq == 0 means no mapping, that should be reported as a + * failure, unless there is an arch-specific fallback handler. + */ + if (!*irq && acpi_gsi_to_irq_fallback) + *irq = acpi_gsi_to_irq_fallback(gsi); + + return (*irq > 0) ? 0 : -EINVAL; +} +EXPORT_SYMBOL_GPL(acpi_gsi_to_irq); + +/** + * acpi_register_gsi() - Map a GSI to a linux IRQ number + * @dev: device for which IRQ has to be mapped + * @gsi: GSI IRQ number + * @trigger: trigger type of the GSI number to be mapped + * @polarity: polarity of the GSI to be mapped + * + * Returns: a valid linux IRQ number on success + * -EINVAL on failure + */ +int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, + int polarity) +{ + struct irq_fwspec fwspec; + unsigned int irq; + + fwspec.fwnode = acpi_get_gsi_domain_id(gsi); + if (WARN_ON(!fwspec.fwnode)) { + pr_warn("GSI: No registered irqchip, giving up\n"); + return -EINVAL; + } + + fwspec.param[0] = gsi; + fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity); + fwspec.param_count = 2; + + irq = irq_create_fwspec_mapping(&fwspec); + if (!irq) + return -EINVAL; + + return irq; +} +EXPORT_SYMBOL_GPL(acpi_register_gsi); + +/** + * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping + * @gsi: GSI IRQ number + */ +void acpi_unregister_gsi(u32 gsi) +{ + struct irq_domain *d; + int irq; + + if (WARN_ON(acpi_irq_model == ACPI_IRQ_MODEL_GIC && gsi < 16)) + return; + + d = irq_find_matching_fwnode(acpi_get_gsi_domain_id(gsi), + DOMAIN_BUS_ANY); + irq = irq_find_mapping(d, gsi); + irq_dispose_mapping(irq); +} +EXPORT_SYMBOL_GPL(acpi_unregister_gsi); + +/** + * acpi_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source. + * @source: acpi_resource_source to use for the lookup. + * @gsi: GSI IRQ number + * + * Description: + * Retrieve the fwhandle of the device referenced by the given IRQ resource + * source. + * + * Return: + * The referenced device fwhandle or NULL on failure + */ +static struct fwnode_handle * +acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source, + u32 gsi) +{ + struct fwnode_handle *result; + struct acpi_device *device; + acpi_handle handle; + acpi_status status; + + if (!source->string_length) + return acpi_get_gsi_domain_id(gsi); + + status = acpi_get_handle(NULL, source->string_ptr, &handle); + if (WARN_ON(ACPI_FAILURE(status))) + return NULL; + + device = acpi_get_acpi_dev(handle); + if (WARN_ON(!device)) + return NULL; + + result = &device->fwnode; + acpi_put_acpi_dev(device); + return result; +} + +/* + * Context for the resource walk used to lookup IRQ resources. + * Contains a return code, the lookup index, and references to the flags + * and fwspec where the result is returned. + */ +struct acpi_irq_parse_one_ctx { + int rc; + unsigned int index; + unsigned long *res_flags; + struct irq_fwspec *fwspec; +}; + +/** + * acpi_irq_parse_one_match - Handle a matching IRQ resource. + * @fwnode: matching fwnode + * @hwirq: hardware IRQ number + * @triggering: triggering attributes of hwirq + * @polarity: polarity attributes of hwirq + * @polarity: polarity attributes of hwirq + * @shareable: shareable attributes of hwirq + * @wake_capable: wake capable attribute of hwirq + * @ctx: acpi_irq_parse_one_ctx updated by this function + * + * Description: + * Handle a matching IRQ resource by populating the given ctx with + * the information passed. + */ +static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode, + u32 hwirq, u8 triggering, + u8 polarity, u8 shareable, + u8 wake_capable, + struct acpi_irq_parse_one_ctx *ctx) +{ + if (!fwnode) + return; + ctx->rc = 0; + *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable, wake_capable); + ctx->fwspec->fwnode = fwnode; + ctx->fwspec->param[0] = hwirq; + ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity); + ctx->fwspec->param_count = 2; +} + +/** + * acpi_irq_parse_one_cb - Handle the given resource. + * @ares: resource to handle + * @context: context for the walk + * + * Description: + * This is called by acpi_walk_resources passing each resource returned by + * the _CRS method. We only inspect IRQ resources. Since IRQ resources + * might contain multiple interrupts we check if the index is within this + * one's interrupt array, otherwise we subtract the current resource IRQ + * count from the lookup index to prepare for the next resource. + * Once a match is found we call acpi_irq_parse_one_match to populate + * the result and end the walk by returning AE_CTRL_TERMINATE. + * + * Return: + * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching + * IRQ resource was found. + */ +static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares, + void *context) +{ + struct acpi_irq_parse_one_ctx *ctx = context; + struct acpi_resource_irq *irq; + struct acpi_resource_extended_irq *eirq; + struct fwnode_handle *fwnode; + + switch (ares->type) { + case ACPI_RESOURCE_TYPE_IRQ: + irq = &ares->data.irq; + if (ctx->index >= irq->interrupt_count) { + ctx->index -= irq->interrupt_count; + return AE_OK; + } + fwnode = acpi_get_gsi_domain_id(irq->interrupts[ctx->index]); + acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index], + irq->triggering, irq->polarity, + irq->shareable, irq->wake_capable, ctx); + return AE_CTRL_TERMINATE; + case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: + eirq = &ares->data.extended_irq; + if (eirq->producer_consumer == ACPI_PRODUCER) + return AE_OK; + if (ctx->index >= eirq->interrupt_count) { + ctx->index -= eirq->interrupt_count; + return AE_OK; + } + fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source, + eirq->interrupts[ctx->index]); + acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index], + eirq->triggering, eirq->polarity, + eirq->shareable, eirq->wake_capable, ctx); + return AE_CTRL_TERMINATE; + } + + return AE_OK; +} + +/** + * acpi_irq_parse_one - Resolve an interrupt for a device + * @handle: the device whose interrupt is to be resolved + * @index: index of the interrupt to resolve + * @fwspec: structure irq_fwspec filled by this function + * @flags: resource flags filled by this function + * + * Description: + * Resolves an interrupt for a device by walking its CRS resources to find + * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec + * and flags. + * + * Return: + * The result stored in ctx.rc by the callback, or the default -EINVAL value + * if an error occurs. + */ +static int acpi_irq_parse_one(acpi_handle handle, unsigned int index, + struct irq_fwspec *fwspec, unsigned long *flags) +{ + struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec }; + + acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx); + return ctx.rc; +} + +/** + * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource. + * @handle: ACPI device handle + * @index: ACPI IRQ resource index to lookup + * @res: Linux IRQ resource to initialize + * + * Description: + * Look for the ACPI IRQ resource with the given index and use it to initialize + * the given Linux IRQ resource. + * + * Return: + * 0 on success + * -EINVAL if an error occurs + * -EPROBE_DEFER if the IRQ lookup/conversion failed + */ +int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res) +{ + struct irq_fwspec fwspec; + struct irq_domain *domain; + unsigned long flags; + int rc; + + rc = acpi_irq_parse_one(handle, index, &fwspec, &flags); + if (rc) + return rc; + + domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY); + if (!domain) + return -EPROBE_DEFER; + + rc = irq_create_fwspec_mapping(&fwspec); + if (rc <= 0) + return -EINVAL; + + res->start = rc; + res->end = rc; + res->flags = flags; + + return 0; +} +EXPORT_SYMBOL_GPL(acpi_irq_get); + +/** + * acpi_set_irq_model - Setup the GSI irqdomain information + * @model: the value assigned to acpi_irq_model + * @fn: a dispatcher function that will return the domain fwnode + * for a given GSI + */ +void __init acpi_set_irq_model(enum acpi_irq_model_id model, + struct fwnode_handle *(*fn)(u32)) +{ + acpi_irq_model = model; + acpi_get_gsi_domain_id = fn; +} + +/** + * acpi_set_gsi_to_irq_fallback - Register a GSI transfer + * callback to fallback to arch specified implementation. + * @fn: arch-specific fallback handler + */ +void __init acpi_set_gsi_to_irq_fallback(u32 (*fn)(u32)) +{ + acpi_gsi_to_irq_fallback = fn; +} + +/** + * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default + * GSI domain as its parent. + * @flags: Irq domain flags associated with the domain + * @size: Size of the domain. + * @fwnode: Optional fwnode of the interrupt controller + * @ops: Pointer to the interrupt domain callbacks + * @host_data: Controller private data pointer + */ +struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags, + unsigned int size, + struct fwnode_handle *fwnode, + const struct irq_domain_ops *ops, + void *host_data) +{ + struct irq_domain *d; + + /* This only works for the GIC model... */ + if (acpi_irq_model != ACPI_IRQ_MODEL_GIC) + return NULL; + + d = irq_find_matching_fwnode(acpi_get_gsi_domain_id(0), + DOMAIN_BUS_ANY); + + if (!d) + return NULL; + + return irq_domain_create_hierarchy(d, flags, size, fwnode, ops, + host_data); +} +EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy); |