1/* SPDX-License-Identifier: MIT */
2
3/*
4 * The VGA aribiter manages VGA space routing and VGA resource decode to
5 * allow multiple VGA devices to be used in a system in a safe way.
6 *
7 * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
8 * (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
9 * (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
10 */
11
12#ifndef LINUX_VGA_H
13#define LINUX_VGA_H
14
15#include <video/vga.h>
16
17struct pci_dev;
18
19/* Legacy VGA regions */
20#define VGA_RSRC_NONE 0x00
21#define VGA_RSRC_LEGACY_IO 0x01
22#define VGA_RSRC_LEGACY_MEM 0x02
23#define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)
24/* Non-legacy access */
25#define VGA_RSRC_NORMAL_IO 0x04
26#define VGA_RSRC_NORMAL_MEM 0x08
27
28#ifdef CONFIG_VGA_ARB
29void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes);
30int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
31void vga_put(struct pci_dev *pdev, unsigned int rsrc);
32struct pci_dev *vga_default_device(void);
33void vga_set_default_device(struct pci_dev *pdev);
34int vga_remove_vgacon(struct pci_dev *pdev);
35int vga_client_register(struct pci_dev *pdev,
36 unsigned int (*set_decode)(struct pci_dev *pdev, bool state));
37#else /* CONFIG_VGA_ARB */
38static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
39 unsigned int decodes)
40{
41};
42static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc,
43 int interruptible)
44{
45 return 0;
46}
47static inline void vga_put(struct pci_dev *pdev, unsigned int rsrc)
48{
49}
50static inline struct pci_dev *vga_default_device(void)
51{
52 return NULL;
53}
54static inline void vga_set_default_device(struct pci_dev *pdev)
55{
56}
57static inline int vga_remove_vgacon(struct pci_dev *pdev)
58{
59 return 0;
60}
61static inline int vga_client_register(struct pci_dev *pdev,
62 unsigned int (*set_decode)(struct pci_dev *pdev, bool state))
63{
64 return 0;
65}
66#endif /* CONFIG_VGA_ARB */
67
68/**
69 * vga_get_interruptible
70 * @pdev: pci device of the VGA card or NULL for the system default
71 * @rsrc: bit mask of resources to acquire and lock
72 *
73 * Shortcut to vga_get with interruptible set to true.
74 *
75 * On success, release the VGA resource again with vga_put().
76 */
77static inline int vga_get_interruptible(struct pci_dev *pdev,
78 unsigned int rsrc)
79{
80 return vga_get(pdev, rsrc, interruptible: 1);
81}
82
83/**
84 * vga_get_uninterruptible - shortcut to vga_get()
85 * @pdev: pci device of the VGA card or NULL for the system default
86 * @rsrc: bit mask of resources to acquire and lock
87 *
88 * Shortcut to vga_get with interruptible set to false.
89 *
90 * On success, release the VGA resource again with vga_put().
91 */
92static inline int vga_get_uninterruptible(struct pci_dev *pdev,
93 unsigned int rsrc)
94{
95 return vga_get(pdev, rsrc, interruptible: 0);
96}
97
98static inline void vga_client_unregister(struct pci_dev *pdev)
99{
100 vga_client_register(pdev, NULL);
101}
102
103#endif /* LINUX_VGA_H */
104

source code of linux/include/linux/vgaarb.h