drivers/acpi/acpi_ffh.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Author: Sudeep Holla <sudeep.holla@arm.com>
   4  * Copyright 2022 Arm Limited
   5  */
   6 #include <linux/kernel.h>
   7 #include <linux/acpi.h>
   8 #include <linux/completion.h>
   9 #include <linux/idr.h>
  10 #include <linux/io.h>
  11
  12 #include <linux/arm-smccc.h>
  13
  14 static struct acpi_ffh_info ffh_ctx;
  15
  16 int __weak acpi_ffh_address_space_arch_setup(void *handler_ctxt,
  17                                              void **region_ctxt)
  18 {
  19         return -EOPNOTSUPP;
  20 }
  21
  22 int __weak acpi_ffh_address_space_arch_handler(acpi_integer *value,
  23                                                void *region_context)
  24 {
  25         return -EOPNOTSUPP;
  26 }
  27
  28 static acpi_status
  29 acpi_ffh_address_space_setup(acpi_handle region_handle, u32 function,
  30                              void *handler_context,  void **region_context)
  31 {
  32         return acpi_ffh_address_space_arch_setup(handler_context,
  33                                                  region_context);
  34 }
  35
  36 static acpi_status
  37 acpi_ffh_address_space_handler(u32 function, acpi_physical_address addr,
  38                                u32 bits, acpi_integer *value,
  39                                void *handler_context, void *region_context)
  40 {
  41         return acpi_ffh_address_space_arch_handler(value, region_context);
  42 }
  43
  44 void __init acpi_init_ffh(void)
  45 {
  46         acpi_status status;
  47
  48         status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
  49                                                     ACPI_ADR_SPACE_FIXED_HARDWARE,
  50                                                     &acpi_ffh_address_space_handler,
  51                                                     &acpi_ffh_address_space_setup,
  52                                                     &ffh_ctx);
  53         if (ACPI_FAILURE(status))
  54                 pr_alert("OperationRegion handler could not be installed\n");
  55 }