drivers/acpi/irq.c - arm/linux - Git at Google

 /*
  * ACPI GSI IRQ layer
  *
  * Copyright (C) 2015 ARM Ltd.
  * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #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_gsi_domain_id;

 /**
  * 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 = irq_find_matching_fwnode(acpi_gsi_domain_id,
 							DOMAIN_BUS_ANY);

 	*irq = irq_find_mapping(d, gsi);
 	/*
 	 * *irq == 0 means no mapping, that should
 	 * be reported as a failure
 	 */
 	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;

 	if (WARN_ON(!acpi_gsi_domain_id)) {
 		pr_warn("GSI: No registered irqchip, giving up\n");
 		return -EINVAL;
 	}

 	fwspec.fwnode = acpi_gsi_domain_id;
 	fwspec.param[0] = gsi;
 	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
 	fwspec.param_count = 2;

 	return irq_create_fwspec_mapping(&fwspec);
 }
 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 = irq_find_matching_fwnode(acpi_gsi_domain_id,
 							DOMAIN_BUS_ANY);
 	int 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.
  *
  * 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)
 {
 	struct fwnode_handle *result;
 	struct acpi_device *device;
 	acpi_handle handle;
 	acpi_status status;

 	if (!source->string_length)
 		return acpi_gsi_domain_id;

 	status = acpi_get_handle(NULL, source->string_ptr, &handle);
 	if (WARN_ON(ACPI_FAILURE(status)))
 		return NULL;

 	device = acpi_bus_get_acpi_device(handle);
 	if (WARN_ON(!device))
 		return NULL;

 	result = &device->fwnode;
 	acpi_bus_put_acpi_device(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
  * @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,
 					    struct acpi_irq_parse_one_ctx *ctx)
 {
 	if (!fwnode)
 		return;
 	ctx->rc = 0;
 	*ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
 	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_gsi_domain_id;
 		acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
 					 irq->triggering, irq->polarity,
 					 irq->sharable, 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);
 		acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
 					 eirq->triggering, eirq->polarity,
 					 eirq->sharable, 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
  * @fwnode: the irq_domain identifier for mapping and looking up
  *          GSI interrupts
  */
 void __init acpi_set_irq_model(enum acpi_irq_model_id model,
 			       struct fwnode_handle *fwnode)
 {
 	acpi_irq_model = model;
 	acpi_gsi_domain_id = fwnode;
 }
	/*
	* ACPI GSI IRQ layer
	*
	* Copyright (C) 2015 ARM Ltd.
	* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#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_gsi_domain_id;

	/**
	* 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 = irq_find_matching_fwnode(acpi_gsi_domain_id,
	DOMAIN_BUS_ANY);

	*irq = irq_find_mapping(d, gsi);
	/*
	* *irq == 0 means no mapping, that should
	* be reported as a failure
	*/
	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;

	if (WARN_ON(!acpi_gsi_domain_id)) {
	pr_warn("GSI: No registered irqchip, giving up\n");
	return -EINVAL;
	}

	fwspec.fwnode = acpi_gsi_domain_id;
	fwspec.param[0] = gsi;
	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
	fwspec.param_count = 2;

	return irq_create_fwspec_mapping(&fwspec);
	}
	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 = irq_find_matching_fwnode(acpi_gsi_domain_id,
	DOMAIN_BUS_ANY);
	int 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.
	*
	* 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)
	{
	struct fwnode_handle *result;
	struct acpi_device *device;
	acpi_handle handle;
	acpi_status status;

	if (!source->string_length)
	return acpi_gsi_domain_id;

	status = acpi_get_handle(NULL, source->string_ptr, &handle);
	if (WARN_ON(ACPI_FAILURE(status)))
	return NULL;

	device = acpi_bus_get_acpi_device(handle);
	if (WARN_ON(!device))
	return NULL;

	result = &device->fwnode;
	acpi_bus_put_acpi_device(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
	* @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,
	struct acpi_irq_parse_one_ctx *ctx)
	{
	if (!fwnode)
	return;
	ctx->rc = 0;
	*ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
	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_gsi_domain_id;
	acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
	irq->triggering, irq->polarity,
	irq->sharable, 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);
	acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
	eirq->triggering, eirq->polarity,
	eirq->sharable, 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
	* @fwnode: the irq_domain identifier for mapping and looking up
	* GSI interrupts
	*/
	void __init acpi_set_irq_model(enum acpi_irq_model_id model,
	struct fwnode_handle *fwnode)
	{
	acpi_irq_model = model;
	acpi_gsi_domain_id = fwnode;
	}