sound/soc/intel/common/sst-match-acpi.c

   1 /*
   2  * sst_match_apci.c - SST (LPE) match for ACPI enumeration.
   3  *
   4  * Copyright (c) 2013-15, Intel Corporation.
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  */
  16
  17 #include "sst-acpi.h"
  18
  19 static acpi_status sst_acpi_find_name(acpi_handle handle, u32 level,
  20                                       void *context, void **ret)
  21 {
  22         struct acpi_device *adev;
  23         const char *name = NULL;
  24
  25         if (acpi_bus_get_device(handle, &adev))
  26                 return AE_OK;
  27
  28         if (adev->status.present && adev->status.functional) {
  29                 name = acpi_dev_name(adev);
  30                 *(const char **)ret = name;
  31                 return AE_CTRL_TERMINATE;
  32         }
  33
  34         return AE_OK;
  35 }
  36
  37 const char *sst_acpi_find_name_from_hid(const u8 hid[ACPI_ID_LEN])
  38 {
  39         const char *name = NULL;
  40         acpi_status status;
  41
  42         status = acpi_get_devices(hid, sst_acpi_find_name, NULL,
  43                                   (void **)&name);
  44
  45         if (ACPI_FAILURE(status) || name[0] == '\0')
  46                 return NULL;
  47
  48         return name;
  49 }
  50 EXPORT_SYMBOL_GPL(sst_acpi_find_name_from_hid);
  51
  52 static acpi_status sst_acpi_mach_match(acpi_handle handle, u32 level,
  53                                        void *context, void **ret)
  54 {
  55         unsigned long long sta;
  56         acpi_status status;
  57
  58         *(bool *)context = true;
  59         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  60         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
  61                 *(bool *)context = false;
  62
  63         return AE_OK;
  64 }
  65
  66 struct sst_acpi_mach *sst_acpi_find_machine(struct sst_acpi_mach *machines)
  67 {
  68         struct sst_acpi_mach *mach;
  69         bool found = false;
  70
  71         for (mach = machines; mach->id[0]; mach++)
  72                 if (ACPI_SUCCESS(acpi_get_devices(mach->id,
  73                                                   sst_acpi_mach_match,
  74                                                   &found, NULL)) && found)
  75                         return mach;
  76         return NULL;
  77 }
  78 EXPORT_SYMBOL_GPL(sst_acpi_find_machine);
  79
  80 MODULE_LICENSE("GPL v2");
  81 MODULE_DESCRIPTION("Intel Common ACPI Match module");