1/* 2 * PCI operations for the Sega Dreamcast 3 * 4 * Copyright (C) 2001, 2002 M. R. Brown 5 * Copyright (C) 2002, 2003 Paul Mundt 6 * 7 * This file is subject to the terms and conditions of the GNU General Public 8 * License. See the file "COPYING" in the main directory of this archive 9 * for more details. 10 */ 11 12#include <linux/sched.h> 13#include <linux/kernel.h> 14#include <linux/param.h> 15#include <linux/interrupt.h> 16#include <linux/init.h> 17#include <linux/irq.h> 18#include <linux/pci.h> 19#include <linux/module.h> 20#include <linux/io.h> 21#include <mach/pci.h> 22 23/* 24 * The !gapspci_config_access case really shouldn't happen, ever, unless 25 * someone implicitly messes around with the last devfn value.. otherwise we 26 * only support a single device anyways, and if we didn't have a BBA, we 27 * wouldn't make it terribly far through the PCI setup anyways. 28 * 29 * Also, we could very easily support both Type 0 and Type 1 configurations 30 * here, but since it doesn't seem that there is any such implementation in 31 * existence, we don't bother. 32 * 33 * I suppose if someone actually gets around to ripping the chip out of 34 * the BBA and hanging some more devices off of it, then this might be 35 * something to take into consideration. However, due to the cost of the BBA, 36 * and the general lack of activity by DC hardware hackers, this doesn't seem 37 * likely to happen anytime soon. 38 */ 39static int gapspci_config_access(unsigned char bus, unsigned int devfn) 40{ 41 return (bus == 0) && (devfn == 0); 42} 43 44/* 45 * We can also actually read and write in b/w/l sizes! Thankfully this part 46 * was at least done right, and we don't have to do the stupid masking and 47 * shifting that we do on the 7751! Small wonders never cease to amaze. 48 */ 49static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val) 50{ 51 *val = 0xffffffff; 52 53 if (!gapspci_config_access(bus->number, devfn)) 54 return PCIBIOS_DEVICE_NOT_FOUND; 55 56 switch (size) { 57 case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break; 58 case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break; 59 case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break; 60 } 61 62 return PCIBIOS_SUCCESSFUL; 63} 64 65static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val) 66{ 67 if (!gapspci_config_access(bus->number, devfn)) 68 return PCIBIOS_DEVICE_NOT_FOUND; 69 70 switch (size) { 71 case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break; 72 case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break; 73 case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break; 74 } 75 76 return PCIBIOS_SUCCESSFUL; 77} 78 79struct pci_ops gapspci_pci_ops = { 80 .read = gapspci_read, 81 .write = gapspci_write, 82}; 83