include/linux/vgaarb.h

   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
  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
  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  */
  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  */
 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 int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
 114 #else
 115 static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
 116 #endif
 117
 118 #if defined(CONFIG_VGA_ARB)
 119 extern 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
 126 extern struct pci_dev *vga_default_device(void);
 127 extern void vga_set_default_device(struct pci_dev *pdev);
 128 #else
 129 static inline struct pci_dev *vga_default_device(void) { return NULL; };
 130 static inline void vga_set_default_device(struct pci_dev *pdev) { };
 131 #endif
 132
 133 /*
 134  * Architectures should define this if they have several
 135  * independent PCI domains that can afford concurrent VGA
 136  * decoding
 137  */
 138 #ifndef __ARCH_HAS_VGA_CONFLICT
 139 static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
 140 {
 141        return 1;
 142 }
 143 #endif
 144
 145 #if defined(CONFIG_VGA_ARB)
 146 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 #else
 150 static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
 151                                       void (*irq_set_state)(void *cookie, bool state),
 152                                       unsigned int (*set_vga_decode)(void *cookie, bool state))
 153 {
 154         return 0;
 155 }
 156 #endif
 157
 158 #endif /* LINUX_VGA_H */