1/*
2 * The VGA aribiter manages VGA space routing and VGA resource decode to
3 * allow multiple VGA devices to be used in a system in a safe way.
4 *
5 * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
6 * (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
7 * (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
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_H
32#define LINUX_VGA_H
33
34#include <video/vga.h>
35
36/* Legacy VGA regions */
37#define VGA_RSRC_NONE 0x00
38#define VGA_RSRC_LEGACY_IO 0x01
39#define VGA_RSRC_LEGACY_MEM 0x02
40#define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)
41/* Non-legacy access */
42#define VGA_RSRC_NORMAL_IO 0x04
43#define VGA_RSRC_NORMAL_MEM 0x08
44
45/* Passing that instead of a pci_dev to use the system "default"
46 * device, that is the one used by vgacon. Archs will probably
47 * have to provide their own vga_default_device();
48 */
49#define VGA_DEFAULT_DEVICE (NULL)
50
51struct pci_dev;
52
53/* For use by clients */
54
55/**
56 * vga_set_legacy_decoding
57 *
58 * @pdev: pci device of the VGA card
59 * @decodes: bit mask of what legacy regions the card decodes
60 *
61 * Indicates to the arbiter if the card decodes legacy VGA IOs,
62 * legacy VGA Memory, both, or none. All cards default to both,
63 * the card driver (fbdev for example) should tell the arbiter
64 * if it has disabled legacy decoding, so the card can be left
65 * out of the arbitration process (and can be safe to take
66 * interrupts at any time.
67 */
68#if defined(CONFIG_VGA_ARB)
69extern void vga_set_legacy_decoding(struct pci_dev *pdev,
70 unsigned int decodes);
71#else
72static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
73 unsigned int decodes) { };
74#endif
75
76#if defined(CONFIG_VGA_ARB)
77extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
78#else
79static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
80#endif
81
82/**
83 * vga_get_interruptible
84 * @pdev: pci device of the VGA card or NULL for the system default
85 * @rsrc: bit mask of resources to acquire and lock
86 *
87 * Shortcut to vga_get with interruptible set to true.
88 *
89 * On success, release the VGA resource again with vga_put().
90 */
91static inline int vga_get_interruptible(struct pci_dev *pdev,
92 unsigned int rsrc)
93{
94 return vga_get(pdev, rsrc, 1);
95}
96
97/**
98 * vga_get_uninterruptible - shortcut to vga_get()
99 * @pdev: pci device of the VGA card or NULL for the system default
100 * @rsrc: bit mask of resources to acquire and lock
101 *
102 * Shortcut to vga_get with interruptible set to false.
103 *
104 * On success, release the VGA resource again with vga_put().
105 */
106static inline int vga_get_uninterruptible(struct pci_dev *pdev,
107 unsigned int rsrc)
108{
109 return vga_get(pdev, rsrc, 0);
110}
111
112#if defined(CONFIG_VGA_ARB)
113extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
114#else
115static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
116#endif
117
118#if defined(CONFIG_VGA_ARB)
119extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
120#else
121#define vga_put(pdev, rsrc)
122#endif
123
124
125#ifdef CONFIG_VGA_ARB
126extern struct pci_dev *vga_default_device(void);
127extern void vga_set_default_device(struct pci_dev *pdev);
128extern int vga_remove_vgacon(struct pci_dev *pdev);
129#else
130static inline struct pci_dev *vga_default_device(void) { return NULL; };
131static inline void vga_set_default_device(struct pci_dev *pdev) { };
132static inline int vga_remove_vgacon(struct pci_dev *pdev) { return 0; };
133#endif
134
135/*
136 * Architectures should define this if they have several
137 * independent PCI domains that can afford concurrent VGA
138 * decoding
139 */
140#ifndef __ARCH_HAS_VGA_CONFLICT
141static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
142{
143 return 1;
144}
145#endif
146
147#if defined(CONFIG_VGA_ARB)
148int vga_client_register(struct pci_dev *pdev, void *cookie,
149 void (*irq_set_state)(void *cookie, bool state),
150 unsigned int (*set_vga_decode)(void *cookie, bool state));
151#else
152static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
153 void (*irq_set_state)(void *cookie, bool state),
154 unsigned int (*set_vga_decode)(void *cookie, bool state))
155{
156 return 0;
157}
158#endif
159
160#endif /* LINUX_VGA_H */
161