linux/arch/mips/pci/ops-sni.c

90 lines
2.1 KiB
C

/*
* 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.
*
* SNI specific PCI support for RM200/RM300.
*
* Copyright (C) 1997 - 2000, 2003 Ralf Baechle <ralf@linux-mips.org>
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <asm/sni.h>
/*
* It seems that on the RM200 only lower 3 bits of the 5 bit PCI device
* address are decoded. We therefore manually have to reject attempts at
* reading outside this range. Being on the paranoid side we only do this
* test for bus 0 and hope forwarding and decoding work properly for any
* subordinated busses.
*
* ASIC PCI only supports type 1 config cycles.
*/
static int set_config_address(unsigned int busno, unsigned int devfn, int reg)
{
if ((devfn > 255) || (reg > 255))
return PCIBIOS_BAD_REGISTER_NUMBER;
if (busno == 0 && devfn >= PCI_DEVFN(8, 0))
return PCIBIOS_DEVICE_NOT_FOUND;
*(volatile u32 *)PCIMT_CONFIG_ADDRESS =
((busno & 0xff) << 16) |
((devfn & 0xff) << 8) |
(reg & 0xfc);
return PCIBIOS_SUCCESSFUL;
}
static int pcimt_read(struct pci_bus *bus, unsigned int devfn, int reg,
int size, u32 * val)
{
int res;
if ((res = set_config_address(bus->number, devfn, reg)))
return res;
switch (size) {
case 1:
*val = *(volatile u8 *) (PCIMT_CONFIG_DATA + (reg & 3));
break;
case 2:
*val = *(volatile u16 *) (PCIMT_CONFIG_DATA + (reg & 2));
break;
case 4:
*val = *(volatile u32 *) PCIMT_CONFIG_DATA;
break;
}
return 0;
}
static int pcimt_write(struct pci_bus *bus, unsigned int devfn, int reg,
int size, u32 val)
{
int res;
if ((res = set_config_address(bus->number, devfn, reg)))
return res;
switch (size) {
case 1:
*(volatile u8 *) (PCIMT_CONFIG_DATA + (reg & 3)) = val;
break;
case 2:
*(volatile u16 *) (PCIMT_CONFIG_DATA + (reg & 2)) = val;
break;
case 4:
*(volatile u32 *) PCIMT_CONFIG_DATA = val;
break;
}
return 0;
}
struct pci_ops sni_pci_ops = {
.read = pcimt_read,
.write = pcimt_write,
};