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       1                 :            : /*
       2                 :            :  * vga_switcheroo.h - Support for laptop with dual GPU using one set of outputs
       3                 :            :  *
       4                 :            :  * Copyright (c) 2010 Red Hat Inc.
       5                 :            :  * Author : Dave Airlie <airlied@redhat.com>
       6                 :            :  *
       7                 :            :  * Copyright (c) 2015 Lukas Wunner <lukas@wunner.de>
       8                 :            :  *
       9                 :            :  * Permission is hereby granted, free of charge, to any person obtaining a
      10                 :            :  * copy of this software and associated documentation files (the "Software"),
      11                 :            :  * to deal in the Software without restriction, including without limitation
      12                 :            :  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      13                 :            :  * and/or sell copies of the Software, and to permit persons to whom the
      14                 :            :  * Software is furnished to do so, subject to the following conditions:
      15                 :            :  *
      16                 :            :  * The above copyright notice and this permission notice (including the next
      17                 :            :  * paragraph) shall be included in all copies or substantial portions of the
      18                 :            :  * Software.
      19                 :            :  *
      20                 :            :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      21                 :            :  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      22                 :            :  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
      23                 :            :  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      24                 :            :  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
      25                 :            :  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
      26                 :            :  * DEALINGS
      27                 :            :  * IN THE SOFTWARE.
      28                 :            :  *
      29                 :            :  */
      30                 :            : 
      31                 :            : #ifndef _LINUX_VGA_SWITCHEROO_H_
      32                 :            : #define _LINUX_VGA_SWITCHEROO_H_
      33                 :            : 
      34                 :            : #include <linux/fb.h>
      35                 :            : 
      36                 :            : struct pci_dev;
      37                 :            : 
      38                 :            : /**
      39                 :            :  * enum vga_switcheroo_handler_flags_t - handler flags bitmask
      40                 :            :  * @VGA_SWITCHEROO_CAN_SWITCH_DDC: whether the handler is able to switch the
      41                 :            :  *      DDC lines separately. This signals to clients that they should call
      42                 :            :  *      drm_get_edid_switcheroo() to probe the EDID
      43                 :            :  * @VGA_SWITCHEROO_NEEDS_EDP_CONFIG: whether the handler is unable to switch
      44                 :            :  *      the AUX channel separately. This signals to clients that the active
      45                 :            :  *      GPU needs to train the link and communicate the link parameters to the
      46                 :            :  *      inactive GPU (mediated by vga_switcheroo). The inactive GPU may then
      47                 :            :  *      skip the AUX handshake and set up its output with these pre-calibrated
      48                 :            :  *      values (DisplayPort specification v1.1a, section 2.5.3.3)
      49                 :            :  *
      50                 :            :  * Handler flags bitmask. Used by handlers to declare their capabilities upon
      51                 :            :  * registering with vga_switcheroo.
      52                 :            :  */
      53                 :            : enum vga_switcheroo_handler_flags_t {
      54                 :            :         VGA_SWITCHEROO_CAN_SWITCH_DDC   = (1 << 0),
      55                 :            :         VGA_SWITCHEROO_NEEDS_EDP_CONFIG = (1 << 1),
      56                 :            : };
      57                 :            : 
      58                 :            : /**
      59                 :            :  * enum vga_switcheroo_state - client power state
      60                 :            :  * @VGA_SWITCHEROO_OFF: off
      61                 :            :  * @VGA_SWITCHEROO_ON: on
      62                 :            :  * @VGA_SWITCHEROO_NOT_FOUND: client has not registered with vga_switcheroo.
      63                 :            :  *      Only used in vga_switcheroo_get_client_state() which in turn is only
      64                 :            :  *      called from hda_intel.c
      65                 :            :  *
      66                 :            :  * Client power state.
      67                 :            :  */
      68                 :            : enum vga_switcheroo_state {
      69                 :            :         VGA_SWITCHEROO_OFF,
      70                 :            :         VGA_SWITCHEROO_ON,
      71                 :            :         /* below are referred only from vga_switcheroo_get_client_state() */
      72                 :            :         VGA_SWITCHEROO_NOT_FOUND,
      73                 :            : };
      74                 :            : 
      75                 :            : /**
      76                 :            :  * enum vga_switcheroo_client_id - client identifier
      77                 :            :  * @VGA_SWITCHEROO_UNKNOWN_ID: initial identifier assigned to vga clients.
      78                 :            :  *      Determining the id requires the handler, so GPUs are given their
      79                 :            :  *      true id in a delayed fashion in vga_switcheroo_enable()
      80                 :            :  * @VGA_SWITCHEROO_IGD: integrated graphics device
      81                 :            :  * @VGA_SWITCHEROO_DIS: discrete graphics device
      82                 :            :  * @VGA_SWITCHEROO_MAX_CLIENTS: currently no more than two GPUs are supported
      83                 :            :  *
      84                 :            :  * Client identifier. Audio clients use the same identifier & 0x100.
      85                 :            :  */
      86                 :            : enum vga_switcheroo_client_id {
      87                 :            :         VGA_SWITCHEROO_UNKNOWN_ID = 0x1000,
      88                 :            :         VGA_SWITCHEROO_IGD = 0,
      89                 :            :         VGA_SWITCHEROO_DIS,
      90                 :            :         VGA_SWITCHEROO_MAX_CLIENTS,
      91                 :            : };
      92                 :            : 
      93                 :            : /**
      94                 :            :  * struct vga_switcheroo_handler - handler callbacks
      95                 :            :  * @init: initialize handler.
      96                 :            :  *      Optional. This gets called when vga_switcheroo is enabled, i.e. when
      97                 :            :  *      two vga clients have registered. It allows the handler to perform
      98                 :            :  *      some delayed initialization that depends on the existence of the
      99                 :            :  *      vga clients. Currently only the radeon and amdgpu drivers use this.
     100                 :            :  *      The return value is ignored
     101                 :            :  * @switchto: switch outputs to given client.
     102                 :            :  *      Mandatory. For muxless machines this should be a no-op. Returning 0
     103                 :            :  *      denotes success, anything else failure (in which case the switch is
     104                 :            :  *      aborted)
     105                 :            :  * @switch_ddc: switch DDC lines to given client.
     106                 :            :  *      Optional. Should return the previous DDC owner on success or a
     107                 :            :  *      negative int on failure
     108                 :            :  * @power_state: cut or reinstate power of given client.
     109                 :            :  *      Optional. The return value is ignored
     110                 :            :  * @get_client_id: determine if given pci device is integrated or discrete GPU.
     111                 :            :  *      Mandatory
     112                 :            :  *
     113                 :            :  * Handler callbacks. The multiplexer itself. The @switchto and @get_client_id
     114                 :            :  * methods are mandatory, all others may be set to NULL.
     115                 :            :  */
     116                 :            : struct vga_switcheroo_handler {
     117                 :            :         int (*init)(void);
     118                 :            :         int (*switchto)(enum vga_switcheroo_client_id id);
     119                 :            :         int (*switch_ddc)(enum vga_switcheroo_client_id id);
     120                 :            :         int (*power_state)(enum vga_switcheroo_client_id id,
     121                 :            :                            enum vga_switcheroo_state state);
     122                 :            :         enum vga_switcheroo_client_id (*get_client_id)(struct pci_dev *pdev);
     123                 :            : };
     124                 :            : 
     125                 :            : /**
     126                 :            :  * struct vga_switcheroo_client_ops - client callbacks
     127                 :            :  * @set_gpu_state: do the equivalent of suspend/resume for the card.
     128                 :            :  *      Mandatory. This should not cut power to the discrete GPU,
     129                 :            :  *      which is the job of the handler
     130                 :            :  * @reprobe: poll outputs.
     131                 :            :  *      Optional. This gets called after waking the GPU and switching
     132                 :            :  *      the outputs to it
     133                 :            :  * @can_switch: check if the device is in a position to switch now.
     134                 :            :  *      Mandatory. The client should return false if a user space process
     135                 :            :  *      has one of its device files open
     136                 :            :  * @gpu_bound: notify the client id to audio client when the GPU is bound.
     137                 :            :  *
     138                 :            :  * Client callbacks. A client can be either a GPU or an audio device on a GPU.
     139                 :            :  * The @set_gpu_state and @can_switch methods are mandatory, @reprobe may be
     140                 :            :  * set to NULL. For audio clients, the @reprobe member is bogus.
     141                 :            :  * OTOH, @gpu_bound is only for audio clients, and not used for GPU clients.
     142                 :            :  */
     143                 :            : struct vga_switcheroo_client_ops {
     144                 :            :         void (*set_gpu_state)(struct pci_dev *dev, enum vga_switcheroo_state);
     145                 :            :         void (*reprobe)(struct pci_dev *dev);
     146                 :            :         bool (*can_switch)(struct pci_dev *dev);
     147                 :            :         void (*gpu_bound)(struct pci_dev *dev, enum vga_switcheroo_client_id);
     148                 :            : };
     149                 :            : 
     150                 :            : #if defined(CONFIG_VGA_SWITCHEROO)
     151                 :            : void vga_switcheroo_unregister_client(struct pci_dev *dev);
     152                 :            : int vga_switcheroo_register_client(struct pci_dev *dev,
     153                 :            :                                    const struct vga_switcheroo_client_ops *ops,
     154                 :            :                                    bool driver_power_control);
     155                 :            : int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
     156                 :            :                                          const struct vga_switcheroo_client_ops *ops,
     157                 :            :                                          struct pci_dev *vga_dev);
     158                 :            : 
     159                 :            : void vga_switcheroo_client_fb_set(struct pci_dev *dev,
     160                 :            :                                   struct fb_info *info);
     161                 :            : 
     162                 :            : int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
     163                 :            :                                     enum vga_switcheroo_handler_flags_t handler_flags);
     164                 :            : void vga_switcheroo_unregister_handler(void);
     165                 :            : enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void);
     166                 :            : int vga_switcheroo_lock_ddc(struct pci_dev *pdev);
     167                 :            : int vga_switcheroo_unlock_ddc(struct pci_dev *pdev);
     168                 :            : 
     169                 :            : int vga_switcheroo_process_delayed_switch(void);
     170                 :            : 
     171                 :            : bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev);
     172                 :            : enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev);
     173                 :            : 
     174                 :            : int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain);
     175                 :            : void vga_switcheroo_fini_domain_pm_ops(struct device *dev);
     176                 :            : #else
     177                 :            : 
     178                 :          0 : static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {}
     179                 :          0 : static inline int vga_switcheroo_register_client(struct pci_dev *dev,
     180                 :          0 :                 const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return 0; }
     181                 :          0 : static inline void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info) {}
     182                 :            : static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
     183                 :            :                 enum vga_switcheroo_handler_flags_t handler_flags) { return 0; }
     184                 :            : static inline int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
     185                 :            :         const struct vga_switcheroo_client_ops *ops,
     186                 :            :         struct pci_dev *vga_dev) { return 0; }
     187                 :            : static inline void vga_switcheroo_unregister_handler(void) {}
     188                 :          0 : static inline enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return 0; }
     189                 :          0 : static inline int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { return -ENODEV; }
     190                 :          0 : static inline int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { return -ENODEV; }
     191                 :          0 : static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }
     192                 :          0 : static inline bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev) { return false; }
     193                 :            : static inline enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev) { return VGA_SWITCHEROO_ON; }
     194                 :            : 
     195                 :            : static inline int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }
     196                 :            : static inline void vga_switcheroo_fini_domain_pm_ops(struct device *dev) {}
     197                 :            : 
     198                 :            : #endif
     199                 :            : #endif /* _LINUX_VGA_SWITCHEROO_H_ */