https://github.com/torvalds/linux
Tip revision: b2d229d4ddb17db541098b83524d901257e93845 authored by Linus Torvalds on 17 April 2022, 20:57:31 UTC
Linux 5.18-rc3
Linux 5.18-rc3
Tip revision: b2d229d
ops-gt64xxx_pci0.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 1999, 2000, 2004 MIPS Technologies, Inc.
* All rights reserved.
* Authors: Carsten Langgaard <carstenl@mips.com>
* Maciej W. Rozycki <macro@mips.com>
*/
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <asm/gt64120.h>
#define PCI_ACCESS_READ 0
#define PCI_ACCESS_WRITE 1
/*
* PCI configuration cycle AD bus definition
*/
/* Type 0 */
#define PCI_CFG_TYPE0_REG_SHF 0
#define PCI_CFG_TYPE0_FUNC_SHF 8
/* Type 1 */
#define PCI_CFG_TYPE1_REG_SHF 0
#define PCI_CFG_TYPE1_FUNC_SHF 8
#define PCI_CFG_TYPE1_DEV_SHF 11
#define PCI_CFG_TYPE1_BUS_SHF 16
static int gt64xxx_pci0_pcibios_config_access(unsigned char access_type,
struct pci_bus *bus, unsigned int devfn, int where, u32 * data)
{
unsigned char busnum = bus->number;
u32 intr;
if ((busnum == 0) && (devfn >= PCI_DEVFN(31, 0)))
return -1; /* Because of a bug in the galileo (for slot 31). */
/* Clear cause register bits */
GT_WRITE(GT_INTRCAUSE_OFS, ~(GT_INTRCAUSE_MASABORT0_BIT |
GT_INTRCAUSE_TARABORT0_BIT));
/* Setup address */
GT_WRITE(GT_PCI0_CFGADDR_OFS,
(busnum << GT_PCI0_CFGADDR_BUSNUM_SHF) |
(devfn << GT_PCI0_CFGADDR_FUNCTNUM_SHF) |
((where / 4) << GT_PCI0_CFGADDR_REGNUM_SHF) |
GT_PCI0_CFGADDR_CONFIGEN_BIT);
if (access_type == PCI_ACCESS_WRITE) {
if (busnum == 0 && PCI_SLOT(devfn) == 0) {
/*
* The Galileo system controller is acting
* differently than other devices.
*/
GT_WRITE(GT_PCI0_CFGDATA_OFS, *data);
} else
__GT_WRITE(GT_PCI0_CFGDATA_OFS, *data);
} else {
if (busnum == 0 && PCI_SLOT(devfn) == 0) {
/*
* The Galileo system controller is acting
* differently than other devices.
*/
*data = GT_READ(GT_PCI0_CFGDATA_OFS);
} else
*data = __GT_READ(GT_PCI0_CFGDATA_OFS);
}
/* Check for master or target abort */
intr = GT_READ(GT_INTRCAUSE_OFS);
if (intr & (GT_INTRCAUSE_MASABORT0_BIT | GT_INTRCAUSE_TARABORT0_BIT)) {
/* Error occurred */
/* Clear bits */
GT_WRITE(GT_INTRCAUSE_OFS, ~(GT_INTRCAUSE_MASABORT0_BIT |
GT_INTRCAUSE_TARABORT0_BIT));
return -1;
}
return 0;
}
/*
* We can't address 8 and 16 bit words directly. Instead we have to
* read/write a 32bit word and mask/modify the data we actually want.
*/
static int gt64xxx_pci0_pcibios_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 * val)
{
u32 data = 0;
if (gt64xxx_pci0_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
where, &data))
return PCIBIOS_DEVICE_NOT_FOUND;
if (size == 1)
*val = (data >> ((where & 3) << 3)) & 0xff;
else if (size == 2)
*val = (data >> ((where & 3) << 3)) & 0xffff;
else
*val = data;
return PCIBIOS_SUCCESSFUL;
}
static int gt64xxx_pci0_pcibios_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
u32 data = 0;
if (size == 4)
data = val;
else {
if (gt64xxx_pci0_pcibios_config_access(PCI_ACCESS_READ, bus,
devfn, where, &data))
return PCIBIOS_DEVICE_NOT_FOUND;
if (size == 1)
data = (data & ~(0xff << ((where & 3) << 3))) |
(val << ((where & 3) << 3));
else if (size == 2)
data = (data & ~(0xffff << ((where & 3) << 3))) |
(val << ((where & 3) << 3));
}
if (gt64xxx_pci0_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn,
where, &data))
return PCIBIOS_DEVICE_NOT_FOUND;
return PCIBIOS_SUCCESSFUL;
}
struct pci_ops gt64xxx_pci0_ops = {
.read = gt64xxx_pci0_pcibios_read,
.write = gt64xxx_pci0_pcibios_write
};