linux/arch/sh/drivers/pci/ops-sh4.c

110 lines
2.5 KiB
C

/*
* Generic SH-4 / SH-4A PCIC operations (SH7751, SH7780).
*
* Copyright (C) 2002 - 2009 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License v2. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/pci.h>
#include <linux/io.h>
#include <asm/addrspace.h>
#include "pci-sh4.h"
/*
* Direct access to PCI hardware...
*/
#define CONFIG_CMD(bus, devfn, where) \
(0x80000000 | (bus->number << 16) | (devfn << 8) | (where & ~3))
static DEFINE_SPINLOCK(sh4_pci_lock);
/*
* Functions for accessing PCI configuration space with type 1 accesses
*/
static int sh4_pci_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct pci_channel *chan = bus->sysdata;
unsigned long flags;
u32 data;
/*
* PCIPDR may only be accessed as 32 bit words,
* so we must do byte alignment by hand
*/
spin_lock_irqsave(&sh4_pci_lock, flags);
pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
data = pci_read_reg(chan, SH4_PCIPDR);
spin_unlock_irqrestore(&sh4_pci_lock, flags);
switch (size) {
case 1:
*val = (data >> ((where & 3) << 3)) & 0xff;
break;
case 2:
*val = (data >> ((where & 2) << 3)) & 0xffff;
break;
case 4:
*val = data;
break;
default:
return PCIBIOS_FUNC_NOT_SUPPORTED;
}
return PCIBIOS_SUCCESSFUL;
}
/*
* Since SH4 only does 32bit access we'll have to do a read,
* mask,write operation.
* We'll allow an odd byte offset, though it should be illegal.
*/
static int sh4_pci_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
struct pci_channel *chan = bus->sysdata;
unsigned long flags;
int shift;
u32 data;
spin_lock_irqsave(&sh4_pci_lock, flags);
pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
data = pci_read_reg(chan, SH4_PCIPDR);
spin_unlock_irqrestore(&sh4_pci_lock, flags);
switch (size) {
case 1:
shift = (where & 3) << 3;
data &= ~(0xff << shift);
data |= ((val & 0xff) << shift);
break;
case 2:
shift = (where & 2) << 3;
data &= ~(0xffff << shift);
data |= ((val & 0xffff) << shift);
break;
case 4:
data = val;
break;
default:
return PCIBIOS_FUNC_NOT_SUPPORTED;
}
pci_write_reg(chan, data, SH4_PCIPDR);
return PCIBIOS_SUCCESSFUL;
}
struct pci_ops sh4_pci_ops = {
.read = sh4_pci_read,
.write = sh4_pci_write,
};
int __attribute__((weak)) pci_fixup_pcic(struct pci_channel *chan)
{
/* Nothing to do. */
return 0;
}