1 /* 2 * X86 ACPI Utility Functions 3 * 4 * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com> 5 * 6 * Based on various non upstream patches to support the CHT Whiskey Cove PMIC: 7 * Copyright (C) 2013-2015 Intel Corporation. All rights reserved. 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/acpi.h> 15 #include <linux/dmi.h> 16 #include <asm/cpu_device_id.h> 17 #include <asm/intel-family.h> 18 #include "../internal.h" 19 20 /* 21 * Some ACPI devices are hidden (status == 0x0) in recent BIOS-es because 22 * some recent Windows drivers bind to one device but poke at multiple 23 * devices at the same time, so the others get hidden. 24 * 25 * Some BIOS-es (temporarily) hide specific APCI devices to work around Windows 26 * driver bugs. We use DMI matching to match known cases of this. 27 * 28 * We work around this by always reporting ACPI_STA_DEFAULT for these 29 * devices. Note this MUST only be done for devices where this is safe. 30 * 31 * This forcing of devices to be present is limited to specific CPU (SoC) 32 * models both to avoid potentially causing trouble on other models and 33 * because some HIDs are re-used on different SoCs for completely 34 * different devices. 35 */ 36 struct always_present_id { 37 struct acpi_device_id hid[2]; 38 struct x86_cpu_id cpu_ids[2]; 39 struct dmi_system_id dmi_ids[2]; /* Optional */ 40 const char *uid; 41 }; 42 43 #define ICPU(model) { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, } 44 45 #define ENTRY(hid, uid, cpu_models, dmi...) { \ 46 { { hid, }, {} }, \ 47 { cpu_models, {} }, \ 48 { { .matches = dmi }, {} }, \ 49 uid, \ 50 } 51 52 static const struct always_present_id always_present_ids[] = { 53 /* 54 * Bay / Cherry Trail PWM directly poked by GPU driver in win10, 55 * but Linux uses a separate PWM driver, harmless if not used. 56 */ 57 ENTRY("80860F09", "1", ICPU(INTEL_FAM6_ATOM_SILVERMONT1), {}), 58 ENTRY("80862288", "1", ICPU(INTEL_FAM6_ATOM_AIRMONT), {}), 59 /* 60 * The INT0002 device is necessary to clear wakeup interrupt sources 61 * on Cherry Trail devices, without it we get nobody cared IRQ msgs. 62 */ 63 ENTRY("INT0002", "1", ICPU(INTEL_FAM6_ATOM_AIRMONT), {}), 64 }; 65 66 bool acpi_device_always_present(struct acpi_device *adev) 67 { 68 u32 *status = (u32 *)&adev->status; 69 u32 old_status = *status; 70 bool ret = false; 71 unsigned int i; 72 73 /* acpi_match_device_ids checks status, so set it to default */ 74 *status = ACPI_STA_DEFAULT; 75 for (i = 0; i < ARRAY_SIZE(always_present_ids); i++) { 76 if (acpi_match_device_ids(adev, always_present_ids[i].hid)) 77 continue; 78 79 if (!adev->pnp.unique_id || 80 strcmp(adev->pnp.unique_id, always_present_ids[i].uid)) 81 continue; 82 83 if (!x86_match_cpu(always_present_ids[i].cpu_ids)) 84 continue; 85 86 if (always_present_ids[i].dmi_ids[0].matches[0].slot && 87 !dmi_check_system(always_present_ids[i].dmi_ids)) 88 continue; 89 90 if (old_status != ACPI_STA_DEFAULT) /* Log only once */ 91 dev_info(&adev->dev, 92 "Device [%s] is in always present list\n", 93 adev->pnp.bus_id); 94 95 ret = true; 96 break; 97 } 98 *status = old_status; 99 100 return ret; 101 } 102