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 51struct 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) 69extern void vga_set_legacy_decoding(struct pci_dev *pdev, 70 unsigned int decodes); 71#else 72static inline void vga_set_legacy_decoding(struct pci_dev *pdev, 73 unsigned int decodes) { }; 74#endif 75 76#if defined(CONFIG_VGA_ARB) 77extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible); 78#else 79static 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 */ 91static 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 */ 106static 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) 113extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc); 114#else 115static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; } 116#endif 117 118#if defined(CONFIG_VGA_ARB) 119extern 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 126extern struct pci_dev *vga_default_device(void); 127extern void vga_set_default_device(struct pci_dev *pdev); 128extern int vga_remove_vgacon(struct pci_dev *pdev); 129#else 130static inline struct pci_dev *vga_default_device(void) { return NULL; }; 131static inline void vga_set_default_device(struct pci_dev *pdev) { }; 132static inline int vga_remove_vgacon(struct pci_dev *pdev) { return 0; }; 133#endif 134 135/* 136 * Architectures should define this if they have several 137 * independent PCI domains that can afford concurrent VGA 138 * decoding 139 */ 140#ifndef __ARCH_HAS_VGA_CONFLICT 141static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2) 142{ 143 return 1; 144} 145#endif 146 147#if defined(CONFIG_VGA_ARB) 148int vga_client_register(struct pci_dev *pdev, void *cookie, 149 void (*irq_set_state)(void *cookie, bool state), 150 unsigned int (*set_vga_decode)(void *cookie, bool state)); 151#else 152static inline int vga_client_register(struct pci_dev *pdev, void *cookie, 153 void (*irq_set_state)(void *cookie, bool state), 154 unsigned int (*set_vga_decode)(void *cookie, bool state)) 155{ 156 return 0; 157} 158#endif 159 160#endif /* LINUX_VGA_H */ 161