298 lines
8.2 KiB
C
298 lines
8.2 KiB
C
/*
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* ACPI GSI IRQ layer
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*
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* Copyright (C) 2015 ARM Ltd.
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* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/acpi.h>
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#include <linux/irq.h>
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#include <linux/irqdomain.h>
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#include <linux/of.h>
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enum acpi_irq_model_id acpi_irq_model;
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static struct fwnode_handle *acpi_gsi_domain_id;
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/**
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* acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
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* @gsi: GSI IRQ number to map
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* @irq: pointer where linux IRQ number is stored
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*
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* irq location updated with irq value [>0 on success, 0 on failure]
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*
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* Returns: 0 on success
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* -EINVAL on failure
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*/
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int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
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{
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struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
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DOMAIN_BUS_ANY);
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*irq = irq_find_mapping(d, gsi);
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/*
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* *irq == 0 means no mapping, that should
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* be reported as a failure
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*/
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return (*irq > 0) ? 0 : -EINVAL;
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}
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EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
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/**
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* acpi_register_gsi() - Map a GSI to a linux IRQ number
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* @dev: device for which IRQ has to be mapped
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* @gsi: GSI IRQ number
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* @trigger: trigger type of the GSI number to be mapped
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* @polarity: polarity of the GSI to be mapped
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*
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* Returns: a valid linux IRQ number on success
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* -EINVAL on failure
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*/
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int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
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int polarity)
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{
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struct irq_fwspec fwspec;
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if (WARN_ON(!acpi_gsi_domain_id)) {
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pr_warn("GSI: No registered irqchip, giving up\n");
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return -EINVAL;
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}
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fwspec.fwnode = acpi_gsi_domain_id;
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fwspec.param[0] = gsi;
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fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
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fwspec.param_count = 2;
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return irq_create_fwspec_mapping(&fwspec);
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}
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EXPORT_SYMBOL_GPL(acpi_register_gsi);
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/**
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* acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
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* @gsi: GSI IRQ number
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*/
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void acpi_unregister_gsi(u32 gsi)
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{
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struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
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DOMAIN_BUS_ANY);
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int irq = irq_find_mapping(d, gsi);
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irq_dispose_mapping(irq);
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}
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EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
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/**
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* acpi_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source.
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* @source: acpi_resource_source to use for the lookup.
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*
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* Description:
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* Retrieve the fwhandle of the device referenced by the given IRQ resource
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* source.
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*
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* Return:
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* The referenced device fwhandle or NULL on failure
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*/
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static struct fwnode_handle *
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acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source)
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{
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struct fwnode_handle *result;
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struct acpi_device *device;
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acpi_handle handle;
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acpi_status status;
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if (!source->string_length)
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return acpi_gsi_domain_id;
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status = acpi_get_handle(NULL, source->string_ptr, &handle);
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if (WARN_ON(ACPI_FAILURE(status)))
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return NULL;
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device = acpi_bus_get_acpi_device(handle);
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if (WARN_ON(!device))
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return NULL;
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result = &device->fwnode;
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acpi_bus_put_acpi_device(device);
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return result;
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}
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/*
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* Context for the resource walk used to lookup IRQ resources.
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* Contains a return code, the lookup index, and references to the flags
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* and fwspec where the result is returned.
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*/
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struct acpi_irq_parse_one_ctx {
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int rc;
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unsigned int index;
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unsigned long *res_flags;
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struct irq_fwspec *fwspec;
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};
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/**
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* acpi_irq_parse_one_match - Handle a matching IRQ resource.
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* @fwnode: matching fwnode
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* @hwirq: hardware IRQ number
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* @triggering: triggering attributes of hwirq
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* @polarity: polarity attributes of hwirq
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* @polarity: polarity attributes of hwirq
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* @shareable: shareable attributes of hwirq
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* @ctx: acpi_irq_parse_one_ctx updated by this function
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*
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* Description:
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* Handle a matching IRQ resource by populating the given ctx with
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* the information passed.
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*/
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static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
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u32 hwirq, u8 triggering,
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u8 polarity, u8 shareable,
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struct acpi_irq_parse_one_ctx *ctx)
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{
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if (!fwnode)
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return;
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ctx->rc = 0;
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*ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
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ctx->fwspec->fwnode = fwnode;
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ctx->fwspec->param[0] = hwirq;
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ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
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ctx->fwspec->param_count = 2;
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}
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/**
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* acpi_irq_parse_one_cb - Handle the given resource.
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* @ares: resource to handle
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* @context: context for the walk
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*
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* Description:
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* This is called by acpi_walk_resources passing each resource returned by
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* the _CRS method. We only inspect IRQ resources. Since IRQ resources
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* might contain multiple interrupts we check if the index is within this
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* one's interrupt array, otherwise we subtract the current resource IRQ
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* count from the lookup index to prepare for the next resource.
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* Once a match is found we call acpi_irq_parse_one_match to populate
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* the result and end the walk by returning AE_CTRL_TERMINATE.
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*
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* Return:
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* AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching
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* IRQ resource was found.
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*/
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static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
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void *context)
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{
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struct acpi_irq_parse_one_ctx *ctx = context;
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struct acpi_resource_irq *irq;
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struct acpi_resource_extended_irq *eirq;
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struct fwnode_handle *fwnode;
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switch (ares->type) {
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case ACPI_RESOURCE_TYPE_IRQ:
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irq = &ares->data.irq;
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if (ctx->index >= irq->interrupt_count) {
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ctx->index -= irq->interrupt_count;
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return AE_OK;
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}
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fwnode = acpi_gsi_domain_id;
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acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
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irq->triggering, irq->polarity,
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irq->sharable, ctx);
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return AE_CTRL_TERMINATE;
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case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
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eirq = &ares->data.extended_irq;
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if (eirq->producer_consumer == ACPI_PRODUCER)
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return AE_OK;
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if (ctx->index >= eirq->interrupt_count) {
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ctx->index -= eirq->interrupt_count;
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return AE_OK;
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}
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fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source);
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acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
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eirq->triggering, eirq->polarity,
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eirq->sharable, ctx);
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return AE_CTRL_TERMINATE;
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}
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return AE_OK;
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}
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/**
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* acpi_irq_parse_one - Resolve an interrupt for a device
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* @handle: the device whose interrupt is to be resolved
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* @index: index of the interrupt to resolve
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* @fwspec: structure irq_fwspec filled by this function
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* @flags: resource flags filled by this function
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*
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* Description:
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* Resolves an interrupt for a device by walking its CRS resources to find
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* the appropriate ACPI IRQ resource and populating the given struct irq_fwspec
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* and flags.
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*
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* Return:
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* The result stored in ctx.rc by the callback, or the default -EINVAL value
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* if an error occurs.
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*/
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static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,
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struct irq_fwspec *fwspec, unsigned long *flags)
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{
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struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };
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acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx);
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return ctx.rc;
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}
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/**
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* acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource.
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* @handle: ACPI device handle
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* @index: ACPI IRQ resource index to lookup
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* @res: Linux IRQ resource to initialize
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*
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* Description:
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* Look for the ACPI IRQ resource with the given index and use it to initialize
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* the given Linux IRQ resource.
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*
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* Return:
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* 0 on success
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* -EINVAL if an error occurs
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* -EPROBE_DEFER if the IRQ lookup/conversion failed
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*/
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int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
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{
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struct irq_fwspec fwspec;
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struct irq_domain *domain;
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unsigned long flags;
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int rc;
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rc = acpi_irq_parse_one(handle, index, &fwspec, &flags);
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if (rc)
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return rc;
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domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
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if (!domain)
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return -EPROBE_DEFER;
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rc = irq_create_fwspec_mapping(&fwspec);
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if (rc <= 0)
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return -EINVAL;
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res->start = rc;
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res->end = rc;
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res->flags = flags;
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return 0;
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}
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EXPORT_SYMBOL_GPL(acpi_irq_get);
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/**
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* acpi_set_irq_model - Setup the GSI irqdomain information
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* @model: the value assigned to acpi_irq_model
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* @fwnode: the irq_domain identifier for mapping and looking up
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* GSI interrupts
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*/
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void __init acpi_set_irq_model(enum acpi_irq_model_id model,
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struct fwnode_handle *fwnode)
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{
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acpi_irq_model = model;
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acpi_gsi_domain_id = fwnode;
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}
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