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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 
51 struct 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)
69 extern void vga_set_legacy_decoding(struct pci_dev *pdev,
70 				    unsigned int decodes);
71 #else
vga_set_legacy_decoding(struct pci_dev * pdev,unsigned int decodes)72 static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
73 					   unsigned int decodes) { };
74 #endif
75 
76 #if defined(CONFIG_VGA_ARB)
77 extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
78 #else
vga_get(struct pci_dev * pdev,unsigned int rsrc,int interruptible)79 static 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  */
vga_get_interruptible(struct pci_dev * pdev,unsigned int rsrc)91 static 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  */
vga_get_uninterruptible(struct pci_dev * pdev,unsigned int rsrc)106 static 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)
113 extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
114 #else
115 #define vga_put(pdev, rsrc)
116 #endif
117 
118 
119 #ifdef CONFIG_VGA_ARB
120 extern struct pci_dev *vga_default_device(void);
121 extern void vga_set_default_device(struct pci_dev *pdev);
122 extern int vga_remove_vgacon(struct pci_dev *pdev);
123 #else
vga_default_device(void)124 static inline struct pci_dev *vga_default_device(void) { return NULL; };
vga_set_default_device(struct pci_dev * pdev)125 static inline void vga_set_default_device(struct pci_dev *pdev) { };
vga_remove_vgacon(struct pci_dev * pdev)126 static inline int vga_remove_vgacon(struct pci_dev *pdev) { return 0; };
127 #endif
128 
129 /*
130  * Architectures should define this if they have several
131  * independent PCI domains that can afford concurrent VGA
132  * decoding
133  */
134 #ifndef __ARCH_HAS_VGA_CONFLICT
vga_conflicts(struct pci_dev * p1,struct pci_dev * p2)135 static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
136 {
137        return 1;
138 }
139 #endif
140 
141 #if defined(CONFIG_VGA_ARB)
142 int vga_client_register(struct pci_dev *pdev, void *cookie,
143 			void (*irq_set_state)(void *cookie, bool state),
144 			unsigned int (*set_vga_decode)(void *cookie, bool state));
145 #else
vga_client_register(struct pci_dev * pdev,void * cookie,void (* irq_set_state)(void * cookie,bool state),unsigned int (* set_vga_decode)(void * cookie,bool state))146 static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
147 				      void (*irq_set_state)(void *cookie, bool state),
148 				      unsigned int (*set_vga_decode)(void *cookie, bool state))
149 {
150 	return 0;
151 }
152 #endif
153 
154 #endif /* LINUX_VGA_H */
155