80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* PCI operations for the Sega Dreamcast
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*
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* Copyright (C) 2001, 2002 M. R. Brown
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* Copyright (C) 2002, 2003 Paul Mundt
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/irq.h>
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#include <linux/pci.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <mach/pci.h>
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/*
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* The !gapspci_config_access case really shouldn't happen, ever, unless
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* someone implicitly messes around with the last devfn value.. otherwise we
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* only support a single device anyways, and if we didn't have a BBA, we
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* wouldn't make it terribly far through the PCI setup anyways.
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*
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* Also, we could very easily support both Type 0 and Type 1 configurations
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* here, but since it doesn't seem that there is any such implementation in
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* existence, we don't bother.
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*
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* I suppose if someone actually gets around to ripping the chip out of
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* the BBA and hanging some more devices off of it, then this might be
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* something to take into consideration. However, due to the cost of the BBA,
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* and the general lack of activity by DC hardware hackers, this doesn't seem
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* likely to happen anytime soon.
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*/
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static int gapspci_config_access(unsigned char bus, unsigned int devfn)
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{
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return (bus == 0) && (devfn == 0);
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}
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/*
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* We can also actually read and write in b/w/l sizes! Thankfully this part
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* was at least done right, and we don't have to do the stupid masking and
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* shifting that we do on the 7751! Small wonders never cease to amaze.
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*/
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static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
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{
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*val = 0xffffffff;
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if (!gapspci_config_access(bus->number, devfn))
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return PCIBIOS_DEVICE_NOT_FOUND;
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switch (size) {
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case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
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case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
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case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
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}
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return PCIBIOS_SUCCESSFUL;
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}
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static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
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{
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if (!gapspci_config_access(bus->number, devfn))
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return PCIBIOS_DEVICE_NOT_FOUND;
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switch (size) {
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case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
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case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
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case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
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}
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return PCIBIOS_SUCCESSFUL;
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}
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struct pci_ops gapspci_pci_ops = {
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.read = gapspci_read,
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.write = gapspci_write,
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};
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