alistair23-linux/drivers/acpi/gsi.c
Marc Zyngier 462e4fc793 acpi/gsi: Cleanup acpi_register_gsi
As the only user of drivers/acpi/gsi.c is now using acpi_set_irq_model
to set acpi_gsi_domain_id to something meaningful, we can always rely
on that information to be present (its absence is an error), and
guarantee that new interrupt controllers will use this API.

Take this opportunity to cleanup acpi_register_gsi.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-and-tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Graeme Gregory <graeme@xora.org.uk>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1444737105-31573-15-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-13 19:01:25 +02:00

118 lines
3 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;
}