/*
* The VGA aribiter manages VGA space routing and VGA resource decode to
* allow multiple VGA devices to be used in a system in a safe way.
*
* (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
* (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
* (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS
* IN THE SOFTWARE.
*
*/
#ifndef LINUX_VGA_H
#define LINUX_VGA_H
#include <video/vga.h>
/* Legacy VGA regions */
#define VGA_RSRC_NONE 0x00
#define VGA_RSRC_LEGACY_IO 0x01
#define VGA_RSRC_LEGACY_MEM 0x02
#define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)
/* Non-legacy access */
#define VGA_RSRC_NORMAL_IO 0x04
#define VGA_RSRC_NORMAL_MEM 0x08
/* Passing that instead of a pci_dev to use the system "default"
* device, that is the one used by vgacon. Archs will probably
* have to provide their own vga_default_device();
*/
#define VGA_DEFAULT_DEVICE (NULL)
struct pci_dev;
/* For use by clients */
/**
* vga_set_legacy_decoding
*
* @pdev: pci device of the VGA card
* @decodes: bit mask of what legacy regions the card decodes
*
* Indicates to the arbiter if the card decodes legacy VGA IOs,
* legacy VGA Memory, both, or none. All cards default to both,
* the card driver (fbdev for example) should tell the arbiter
* if it has disabled legacy decoding, so the card can be left
* out of the arbitration process (and can be safe to take
* interrupts at any time.
*/
extern void vga_set_legacy_decoding(struct pci_dev *pdev,
unsigned int decodes);
/**
* vga_get - acquire & locks VGA resources
*
* @pdev: pci device of the VGA card or NULL for the system default
* @rsrc: bit mask of resources to acquire and lock
* @interruptible: blocking should be interruptible by signals ?
*
* This function acquires VGA resources for the given
* card and mark those resources locked. If the resource requested
* are "normal" (and not legacy) resources, the arbiter will first check
* whether the card is doing legacy decoding for that type of resource. If
* yes, the lock is "converted" into a legacy resource lock.
* The arbiter will first look for all VGA cards that might conflict
* and disable their IOs and/or Memory access, including VGA forwarding
* on P2P bridges if necessary, so that the requested resources can
* be used. Then, the card is marked as locking these resources and
* the IO and/or Memory accesse are enabled on the card (including
* VGA forwarding on parent P2P bridges if any).
* This function will block if some conflicting card is already locking
* one of the required resources (or any resource on a different bus
* segment, since P2P bridges don't differenciate VGA memory and IO
* afaik). You can indicate whether this blocking should be interruptible
* by a signal (for userland interface) or not.
* Must not be called at interrupt time or in atomic context.
* If the card already owns the resources, the function succeeds.
* Nested calls are supported (a per-resource counter is maintained)
*/
#if defined(CONFIG_VGA_ARB)
extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
#else
static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
#endif
/**
* vga_get_interruptible
*
* Shortcut to vga_get
*/
static inline int vga_get_interruptible(struct pci_dev *pdev,
unsigned int rsrc)
{
return vga_get(pdev, rsrc, 1);
}
/**
* vga_get_uninterruptible
*
* Shortcut to vga_get
*/
static inline int vga_get_uninterruptible(struct pci_dev *pdev,
unsigned int rsrc)
{
return vga_get(pdev, rsrc, 0);
}
/**
* vga_tryget - try to acquire & lock legacy VGA resources
*
* @pdev: pci devivce of VGA card or NULL for system default
