/*

   * vga_switcheroo.h - Support for laptop with dual GPU using one set of outputs
   *

   * Copyright (c) 2010 Red Hat Inc.
   * Author : Dave Airlie <airlied@redhat.com>
   *

   * Copyright (c) 2015 Lukas Wunner <lukas@wunner.de>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS
   * IN THE SOFTWARE.

   *

   */

  #ifndef _LINUX_VGA_SWITCHEROO_H_
  #define _LINUX_VGA_SWITCHEROO_H_

  #include <linux/fb.h>

  struct pci_dev;

  /**

   * enum vga_switcheroo_handler_flags_t - handler flags bitmask
   * @VGA_SWITCHEROO_CAN_SWITCH_DDC: whether the handler is able to switch the
   * 	DDC lines separately. This signals to clients that they should call
   * 	drm_get_edid_switcheroo() to probe the EDID
   * @VGA_SWITCHEROO_NEEDS_EDP_CONFIG: whether the handler is unable to switch
   * 	the AUX channel separately. This signals to clients that the active
   * 	GPU needs to train the link and communicate the link parameters to the
   * 	inactive GPU (mediated by vga_switcheroo). The inactive GPU may then
   * 	skip the AUX handshake and set up its output with these pre-calibrated
   * 	values (DisplayPort specification v1.1a, section 2.5.3.3)
   *
   * Handler flags bitmask. Used by handlers to declare their capabilities upon
   * registering with vga_switcheroo.
   */
  enum vga_switcheroo_handler_flags_t {
  	VGA_SWITCHEROO_CAN_SWITCH_DDC	= (1 << 0),
  	VGA_SWITCHEROO_NEEDS_EDP_CONFIG	= (1 << 1),
  };
  
  /**

   * enum vga_switcheroo_state - client power state
   * @VGA_SWITCHEROO_OFF: off
   * @VGA_SWITCHEROO_ON: on

   * @VGA_SWITCHEROO_NOT_FOUND: client has not registered with vga_switcheroo.
   * 	Only used in vga_switcheroo_get_client_state() which in turn is only
   * 	called from hda_intel.c
   *
   * Client power state.
   */

  enum vga_switcheroo_state {
  	VGA_SWITCHEROO_OFF,
  	VGA_SWITCHEROO_ON,

  	/* below are referred only from vga_switcheroo_get_client_state() */

  	VGA_SWITCHEROO_NOT_FOUND,

  };

  /**
   * enum vga_switcheroo_client_id - client identifier

   * @VGA_SWITCHEROO_UNKNOWN_ID: initial identifier assigned to vga clients.
   * 	Determining the id requires the handler, so GPUs are given their
   * 	true id in a delayed fashion in vga_switcheroo_enable()

   * @VGA_SWITCHEROO_IGD: integrated graphics device
   * @VGA_SWITCHEROO_DIS: discrete graphics device
   * @VGA_SWITCHEROO_MAX_CLIENTS: currently no more than two GPUs are supported
   *
   * Client identifier. Audio clients use the same identifier & 0x100.
   */

  enum vga_switcheroo_client_id {

  	VGA_SWITCHEROO_UNKNOWN_ID = 0x1000,
  	VGA_SWITCHEROO_IGD = 0,

  	VGA_SWITCHEROO_DIS,
  	VGA_SWITCHEROO_MAX_CLIENTS,
  };

  /**
   * struct vga_switcheroo_handler - handler callbacks
   * @init: initialize handler.
   * 	Optional. This gets called when vga_switcheroo is enabled, i.e. when
   * 	two vga clients have registered. It allows the handler to perform
   * 	some delayed initialization that depends on the existence of the
   * 	vga clients. Currently only the radeon and amdgpu drivers use this.
   * 	The return value is ignored
   * @switchto: switch outputs to given client.
   * 	Mandatory. For muxless machines this should be a no-op. Returning 0
   * 	denotes success, anything else failure (in which case the switch is
   * 	aborted)

   * @switch_ddc: switch DDC lines to given client.
   * 	Optional. Should return the previous DDC owner on success or a
   * 	negative int on failure

   * @power_state: cut or reinstate power of given client.
   * 	Optional. The return value is ignored
   * @get_client_id: determine if given pci device is integrated or discrete GPU.
   * 	Mandatory
   *
   * Handler callbacks. The multiplexer itself. The @switchto and @get_client_id
   * methods are mandatory, all others may be set to NULL.
   */

  struct vga_switcheroo_handler {

  	int (*init)(void);

  	int (*switchto)(enum vga_switcheroo_client_id id);

  	int (*switch_ddc)(enum vga_switcheroo_client_id id);

  	int (*power_state)(enum vga_switcheroo_client_id id,
  			   enum vga_switcheroo_state state);

  	enum vga_switcheroo_client_id (*get_client_id)(struct pci_dev *pdev);

  };

  /**
   * struct vga_switcheroo_client_ops - client callbacks
   * @set_gpu_state: do the equivalent of suspend/resume for the card.
   * 	Mandatory. This should not cut power to the discrete GPU,
   * 	which is the job of the handler
   * @reprobe: poll outputs.
   * 	Optional. This gets called after waking the GPU and switching
   * 	the outputs to it
   * @can_switch: check if the device is in a position to switch now.
   * 	Mandatory. The client should return false if a user space process
   * 	has one of its device files open

   * @gpu_bound: notify the client id to audio client when the GPU is bound.

   *
   * Client callbacks. A client can be either a GPU or an audio device on a GPU.
   * The @set_gpu_state and @can_switch methods are mandatory, @reprobe may be
   * set to NULL. For audio clients, the @reprobe member is bogus.

   * OTOH, @gpu_bound is only for audio clients, and not used for GPU clients.

   */

  struct vga_switcheroo_client_ops {
  	void (*set_gpu_state)(struct pci_dev *dev, enum vga_switcheroo_state);
  	void (*reprobe)(struct pci_dev *dev);
  	bool (*can_switch)(struct pci_dev *dev);

  	void (*gpu_bound)(struct pci_dev *dev, enum vga_switcheroo_client_id);

  };

  
  #if defined(CONFIG_VGA_SWITCHEROO)
  void vga_switcheroo_unregister_client(struct pci_dev *dev);
  int vga_switcheroo_register_client(struct pci_dev *dev,

  				   const struct vga_switcheroo_client_ops *ops,
  				   bool driver_power_control);

  int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
  					 const struct vga_switcheroo_client_ops *ops,

  					 struct pci_dev *vga_dev);

  
  void vga_switcheroo_client_fb_set(struct pci_dev *dev,
  				  struct fb_info *info);

  int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
  				    enum vga_switcheroo_handler_flags_t handler_flags);

  void vga_switcheroo_unregister_handler(void);

  enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void);

  int vga_switcheroo_lock_ddc(struct pci_dev *pdev);
  int vga_switcheroo_unlock_ddc(struct pci_dev *pdev);

  
  int vga_switcheroo_process_delayed_switch(void);

  bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev);

  enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev);

  int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain);

  void vga_switcheroo_fini_domain_pm_ops(struct device *dev);

  #else
  
  static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {}
  static inline int vga_switcheroo_register_client(struct pci_dev *dev,

  		const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return 0; }

  static inline void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info) {}

  static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
  		enum vga_switcheroo_handler_flags_t handler_flags) { return 0; }

  static inline int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
  	const struct vga_switcheroo_client_ops *ops,

  	struct pci_dev *vga_dev) { return 0; }

  static inline void vga_switcheroo_unregister_handler(void) {}

  static inline enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return 0; }

  static inline int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { return -ENODEV; }
  static inline int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { return -ENODEV; }

  static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }

  static inline bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev) { return false; }

  static inline enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev) { return VGA_SWITCHEROO_ON; }

  static inline int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }

  static inline void vga_switcheroo_fini_domain_pm_ops(struct device *dev) {}

  
  #endif

  #endif /* _LINUX_VGA_SWITCHEROO_H_ */