include/linux/vga_switcheroo.h

   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 = -1,
  88         VGA_SWITCHEROO_IGD,
  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  *
 137  * Client callbacks. A client can be either a GPU or an audio device on a GPU.
 138  * The @set_gpu_state and @can_switch methods are mandatory, @reprobe may be
 139  * set to NULL. For audio clients, the @reprobe member is bogus.
 140  */
 141 struct vga_switcheroo_client_ops {
 142         void (*set_gpu_state)(struct pci_dev *dev, enum vga_switcheroo_state);
 143         void (*reprobe)(struct pci_dev *dev);
 144         bool (*can_switch)(struct pci_dev *dev);
 145 };
 146
 147 #if defined(CONFIG_VGA_SWITCHEROO)
 148 void vga_switcheroo_unregister_client(struct pci_dev *dev);
 149 int vga_switcheroo_register_client(struct pci_dev *dev,
 150                                    const struct vga_switcheroo_client_ops *ops,
 151                                    bool driver_power_control);
 152 int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
 153                                          const struct vga_switcheroo_client_ops *ops,
 154                                          enum vga_switcheroo_client_id id);
 155
 156 void vga_switcheroo_client_fb_set(struct pci_dev *dev,
 157                                   struct fb_info *info);
 158
 159 int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
 160                                     enum vga_switcheroo_handler_flags_t handler_flags);
 161 void vga_switcheroo_unregister_handler(void);
 162 enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void);
 163 int vga_switcheroo_lock_ddc(struct pci_dev *pdev);
 164 int vga_switcheroo_unlock_ddc(struct pci_dev *pdev);
 165
 166 int vga_switcheroo_process_delayed_switch(void);
 167
 168 bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev);
 169 enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev);
 170
 171 void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic);
 172
 173 int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain);
 174 void vga_switcheroo_fini_domain_pm_ops(struct device *dev);
 175 int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, struct dev_pm_domain *domain);
 176 #else
 177
 178 static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {}
 179 static inline int vga_switcheroo_register_client(struct pci_dev *dev,
 180                 const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return 0; }
 181 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         enum vga_switcheroo_client_id id) { return 0; }
 187 static inline void vga_switcheroo_unregister_handler(void) {}
 188 static inline enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return 0; }
 189 static inline int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { return -ENODEV; }
 190 static inline int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { return -ENODEV; }
 191 static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }
 192 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 void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic) {}
 196
 197 static inline int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }
 198 static inline void vga_switcheroo_fini_domain_pm_ops(struct device *dev) {}
 199 static inline int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }
 200
 201 #endif
 202 #endif /* _LINUX_VGA_SWITCHEROO_H_ */