include/linux/apple-gmux.h

   1 /*
   2  * apple-gmux.h - microcontroller built into dual GPU MacBook Pro & Mac Pro
   3  * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License (version 2) as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef LINUX_APPLE_GMUX_H
  19 #define LINUX_APPLE_GMUX_H
  20
  21 #include <linux/acpi.h>
  22
  23 #define GMUX_ACPI_HID "APP000B"
  24
  25 #if IS_ENABLED(CONFIG_APPLE_GMUX)
  26
  27 /**
  28  * apple_gmux_present() - detect if gmux is built into the machine
  29  *
  30  * Drivers may use this to activate quirks specific to dual GPU MacBook Pros
  31  * and Mac Pros, e.g. for deferred probing, runtime pm and backlight.
  32  *
  33  * Return: %true if gmux is present and the kernel was configured
  34  * with CONFIG_APPLE_GMUX, %false otherwise.
  35  */
  36 static inline bool apple_gmux_present(void)
  37 {
  38         return acpi_dev_found(GMUX_ACPI_HID);
  39 }
  40
  41 #else  /* !CONFIG_APPLE_GMUX */
  42
  43 static inline bool apple_gmux_present(void)
  44 {
  45         return false;
  46 }
  47
  48 #endif /* !CONFIG_APPLE_GMUX */
  49
  50 #endif /* LINUX_APPLE_GMUX_H */