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
36struct 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 */
53enum 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 */
68enum 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 */
86enum 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 */
116struct 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 */
143struct 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)
151void vga_switcheroo_unregister_client(struct pci_dev *dev);
152int vga_switcheroo_register_client(struct pci_dev *dev,
153 const struct vga_switcheroo_client_ops *ops,
154 bool driver_power_control);
155int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
156 const struct vga_switcheroo_client_ops *ops,
157 struct pci_dev *vga_dev);
158
159void vga_switcheroo_client_fb_set(struct pci_dev *dev,
160 struct fb_info *info);
161
162int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
163 enum vga_switcheroo_handler_flags_t handler_flags);
164void vga_switcheroo_unregister_handler(void);
165enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void);
166int vga_switcheroo_lock_ddc(struct pci_dev *pdev);
167int vga_switcheroo_unlock_ddc(struct pci_dev *pdev);
168
169int vga_switcheroo_process_delayed_switch(void);
170
171bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev);
172enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev);
173
174int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain);
175void vga_switcheroo_fini_domain_pm_ops(struct device *dev);
176#else
177
178static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {}
179static inline int vga_switcheroo_register_client(struct pci_dev *dev,
180 const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return 0; }
181static inline void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info) {}
182static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
183 enum vga_switcheroo_handler_flags_t handler_flags) { return 0; }
184static 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; }
187static inline void vga_switcheroo_unregister_handler(void) {}
188static inline enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return 0; }
189static inline int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { return -ENODEV; }
190static inline int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { return -ENODEV; }
191static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }
192static inline bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev) { return false; }
193static inline enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev) { return VGA_SWITCHEROO_ON; }
194
195static inline int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }
196static inline void vga_switcheroo_fini_domain_pm_ops(struct device *dev) {}
197
198#endif
199#endif /* _LINUX_VGA_SWITCHEROO_H_ */
200