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
 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, 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, 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 */