106 lines
2.8 KiB
C
106 lines
2.8 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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enum acpi_irq_model_id acpi_irq_model;
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static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity)
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{
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switch (polarity) {
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case ACPI_ACTIVE_LOW:
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return trigger == ACPI_EDGE_SENSITIVE ?
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IRQ_TYPE_EDGE_FALLING :
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IRQ_TYPE_LEVEL_LOW;
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case ACPI_ACTIVE_HIGH:
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return trigger == ACPI_EDGE_SENSITIVE ?
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IRQ_TYPE_EDGE_RISING :
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IRQ_TYPE_LEVEL_HIGH;
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case ACPI_ACTIVE_BOTH:
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if (trigger == ACPI_EDGE_SENSITIVE)
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return IRQ_TYPE_EDGE_BOTH;
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default:
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return IRQ_TYPE_NONE;
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}
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}
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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: linux IRQ number on success (>0)
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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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/*
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* Only default domain is supported at present, always find
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* the mapping corresponding to default domain by passing NULL
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* as irq_domain parameter
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*/
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*irq = irq_find_mapping(NULL, 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) ? *irq : -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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unsigned int irq;
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unsigned int irq_type = acpi_gsi_get_irq_type(trigger, polarity);
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/*
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* There is no way at present to look-up the IRQ domain on ACPI,
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* hence always create mapping referring to the default domain
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* by passing NULL as irq_domain parameter
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*/
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irq = irq_create_mapping(NULL, gsi);
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if (!irq)
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return -EINVAL;
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/* Set irq type if specified and different than the current one */
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if (irq_type != IRQ_TYPE_NONE &&
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irq_type != irq_get_trigger_type(irq))
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irq_set_irq_type(irq, irq_type);
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return irq;
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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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int irq = irq_find_mapping(NULL, 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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