linux/drivers/acpi/gsi.c

118 lines
3.0 KiB
C

/*
* 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;
static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity)
{
switch (polarity) {
case ACPI_ACTIVE_LOW:
return trigger == ACPI_EDGE_SENSITIVE ?
IRQ_TYPE_EDGE_FALLING :
IRQ_TYPE_LEVEL_LOW;
case ACPI_ACTIVE_HIGH:
return trigger == ACPI_EDGE_SENSITIVE ?
IRQ_TYPE_EDGE_RISING :
IRQ_TYPE_LEVEL_HIGH;
case ACPI_ACTIVE_BOTH:
if (trigger == ACPI_EDGE_SENSITIVE)
return IRQ_TYPE_EDGE_BOTH;
default:
return IRQ_TYPE_NONE;
}
}
/**
* 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: linux IRQ number on success (>0)
* -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) ? *irq : -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_gsi_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_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;
}