linux/arch/sh/drivers/pci/fixups-dreamcast.c
Bjorn Helgaas ace4b3fd67 sh/PCI: Pass GAPSPCI_DMA_BASE CPU & bus address to dma_declare_coherent_memory()
dma_declare_coherent_memory() needs both the CPU physical address and the
bus address of the device memory.  They are the same on this platform, but
in general we should use pcibios_resource_to_bus() to account for any
address translation done by the PCI host bridge.

This makes no difference on Dreamcast, but is safer if the usage is copied
to future drivers.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
CC: Magnus Damm <damm@opensource.se>
CC: linux-sh@vger.kernel.org
2014-05-20 16:55:39 -06:00

90 lines
2.6 KiB
C

/*
* arch/sh/drivers/pci/fixups-dreamcast.c
*
* PCI fixups for the Sega Dreamcast
*
* Copyright (C) 2001, 2002 M. R. Brown
* Copyright (C) 2002, 2003, 2006 Paul Mundt
*
* This file originally bore the message (with enclosed-$):
* Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp
* Dreamcast PCI: Supports SEGA Broadband Adaptor only.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <mach/pci.h>
static void gapspci_fixup_resources(struct pci_dev *dev)
{
struct pci_channel *p = dev->sysdata;
struct resource res;
struct pci_bus_region region;
printk(KERN_NOTICE "PCI: Fixing up device %s\n", pci_name(dev));
switch (dev->device) {
case PCI_DEVICE_ID_SEGA_BBA:
/*
* We also assume that dev->devfn == 0
*/
dev->resource[1].start = p->resources[0].start + 0x100;
dev->resource[1].end = dev->resource[1].start + 0x200 - 1;
/*
* This is not a normal BAR, prevent any attempts to move
* the BAR, as this will result in a bus lock.
*/
dev->resource[1].flags |= IORESOURCE_PCI_FIXED;
/*
* Redirect dma memory allocations to special memory window.
*
* If this GAPSPCI region were mapped by a BAR, the CPU
* phys_addr_t would be pci_resource_start(), and the bus
* address would be pci_bus_address(pci_resource_start()).
* But apparently there's no BAR mapping it, so we just
* "know" its CPU address is GAPSPCI_DMA_BASE.
*/
res.start = GAPSPCI_DMA_BASE;
res.end = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1;
res.flags = IORESOURCE_MEM;
pcibios_resource_to_bus(dev->bus, &region, &res);
BUG_ON(!dma_declare_coherent_memory(&dev->dev,
res.start,
region.start,
resource_size(&res),
DMA_MEMORY_MAP |
DMA_MEMORY_EXCLUSIVE));
break;
default:
printk("PCI: Failed resource fixup\n");
}
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, gapspci_fixup_resources);
int __init pcibios_map_platform_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
/*
* The interrupt routing semantics here are quite trivial.
*
* We basically only support one interrupt, so we only bother
* updating a device's interrupt line with this single shared
* interrupt. Keeps routing quite simple, doesn't it?
*/
return GAPSPCI_IRQ;
}