linux/drivers/acpi/acpi_ffh.c
Sudeep Holla e81c782c16 ACPI: Implement a generic FFH Opregion handler
This registers the FFH OpRegion handler before ACPI tables are
loaded. The platform support for the same is checked via Platform-Wide
OSPM Capabilities(OSC) before registering the OpRegion handler.

It relies on the special context data passed to offset and the length.
However the interpretation of the values is platform/architecture
specific. This generic handler just passed all the information to
the platform/architecture specific callback. It also implements the
default callbacks which return as not supported.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-11-14 19:09:07 +01:00

56 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Author: Sudeep Holla <sudeep.holla@arm.com>
* Copyright 2022 Arm Limited
*/
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/completion.h>
#include <linux/idr.h>
#include <linux/io.h>
#include <linux/arm-smccc.h>
static struct acpi_ffh_info ffh_ctx;
int __weak acpi_ffh_address_space_arch_setup(void *handler_ctxt,
void **region_ctxt)
{
return -EOPNOTSUPP;
}
int __weak acpi_ffh_address_space_arch_handler(acpi_integer *value,
void *region_context)
{
return -EOPNOTSUPP;
}
static acpi_status
acpi_ffh_address_space_setup(acpi_handle region_handle, u32 function,
void *handler_context, void **region_context)
{
return acpi_ffh_address_space_arch_setup(handler_context,
region_context);
}
static acpi_status
acpi_ffh_address_space_handler(u32 function, acpi_physical_address addr,
u32 bits, acpi_integer *value,
void *handler_context, void *region_context)
{
return acpi_ffh_address_space_arch_handler(value, region_context);
}
void __init acpi_init_ffh(void)
{
acpi_status status;
status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
ACPI_ADR_SPACE_FIXED_HARDWARE,
&acpi_ffh_address_space_handler,
&acpi_ffh_address_space_setup,
&ffh_ctx);
if (ACPI_FAILURE(status))
pr_alert("OperationRegion handler could not be installed\n");
}