include/linux/vgaarb.h

   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
  17 struct 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
  29 void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes);
  30 int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
  31 void vga_put(struct pci_dev *pdev, unsigned int rsrc);
  32 struct pci_dev *vga_default_device(void);
  33 void vga_set_default_device(struct pci_dev *pdev);
  34 int vga_remove_vgacon(struct pci_dev *pdev);
  35 int vga_client_register(struct pci_dev *pdev,
  36                 unsigned int (*set_decode)(struct pci_dev *pdev, bool state));
  37 #else /* CONFIG_VGA_ARB */
  38 static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
  39                 unsigned int decodes)
  40 {
  41 };
  42 static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc,
  43                 int interruptible)
  44 {
  45         return 0;
  46 }
  47 static inline void vga_put(struct pci_dev *pdev, unsigned int rsrc)
  48 {
  49 }
  50 static inline struct pci_dev *vga_default_device(void)
  51 {
  52         return NULL;
  53 }
  54 static inline void vga_set_default_device(struct pci_dev *pdev)
  55 {
  56 }
  57 static inline int vga_remove_vgacon(struct pci_dev *pdev)
  58 {
  59         return 0;
  60 }
  61 static 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  */
  77 static inline int vga_get_interruptible(struct pci_dev *pdev,
  78                                         unsigned int rsrc)
  79 {
  80         return vga_get(pdev, rsrc, 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  */
  92 static inline int vga_get_uninterruptible(struct pci_dev *pdev,
  93                                           unsigned int rsrc)
  94 {
  95         return vga_get(pdev, rsrc, 0);
  96 }
  97
  98 static inline void vga_client_unregister(struct pci_dev *pdev)
  99 {
 100         vga_client_register(pdev, NULL);
 101 }
 102
 103 #endif /* LINUX_VGA_H */