|  | /* SPDX-License-Identifier: GPL-2.0-only */ | 
|  | /* | 
|  | * apple-gmux.h - microcontroller built into dual GPU MacBook Pro & Mac Pro | 
|  | * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de> | 
|  | */ | 
|  |  | 
|  | #ifndef LINUX_APPLE_GMUX_H | 
|  | #define LINUX_APPLE_GMUX_H | 
|  |  | 
|  | #include <linux/acpi.h> | 
|  |  | 
|  | #define GMUX_ACPI_HID "APP000B" | 
|  |  | 
|  | #if IS_ENABLED(CONFIG_APPLE_GMUX) | 
|  |  | 
|  | /** | 
|  | * apple_gmux_present() - detect if gmux is built into the machine | 
|  | * | 
|  | * Drivers may use this to activate quirks specific to dual GPU MacBook Pros | 
|  | * and Mac Pros, e.g. for deferred probing, runtime pm and backlight. | 
|  | * | 
|  | * Return: %true if gmux is present and the kernel was configured | 
|  | * with CONFIG_APPLE_GMUX, %false otherwise. | 
|  | */ | 
|  | static inline bool apple_gmux_present(void) | 
|  | { | 
|  | return acpi_dev_found(GMUX_ACPI_HID); | 
|  | } | 
|  |  | 
|  | #else  /* !CONFIG_APPLE_GMUX */ | 
|  |  | 
|  | static inline bool apple_gmux_present(void) | 
|  | { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | #endif /* !CONFIG_APPLE_GMUX */ | 
|  |  | 
|  | #endif /* LINUX_APPLE_GMUX_H */ |