/*
* arch/arm/mach-ixp2000/pci.c
*
* PCI routines for IXDP2400/IXDP2800 boards
*
* Original Author: Naeem Afzal <naeem.m.afzal@intel.com>
* Maintained by: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2002 Intel Corp.
* Copyright (C) 2003-2004 MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#include <asm/hardware.h>
#include <asm/mach/pci.h>
static int pci_master_aborts = 0;
static int clear_master_aborts(void);
u32 *
ixp2000_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
{
u32 *paddress;
if (PCI_SLOT(devfn) > 7)
return 0;
/* Must be dword aligned */
where &= ~3;
/*
* For top bus, generate type 0, else type 1
*/
if (!bus_nr) {
/* only bits[23:16] are used for IDSEL */
paddress = (u32 *) (IXP2000_PCI_CFG0_VIRT_BASE
| (1 << (PCI_SLOT(devfn) + 16))
| (PCI_FUNC(devfn) << 8) | where);
} else {
paddress = (u32 *) (IXP2000_PCI_CFG1_VIRT_BASE
| (bus_nr << 16)
| (PCI_SLOT(devfn) << 11)
| (PCI_FUNC(devfn) << 8) | where);
}
return paddress;
}
/*
* Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
* 0 and 3 are not valid indexes...
*/
static u32 bytemask[] = {
/*0*/ 0,
/*1*/ 0xff,
/*2*/ 0xffff,
/*3*/ 0,
/*4*/ 0xffffffff,
};
int ixp2000_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where,
int size, u32 *value)
{
u32 n;
u32 *addr;
n = where % 4;
addr = ixp2000_pci_config_addr(bus->number, devfn, where);
if (!addr)
return PCIBIOS_DEVICE_NOT_FOUND;
pci_master_aborts = 0;
*value = (*addr >> (8*n)) & bytemask[size];
if (pci_master_aborts) {
pci_master_aborts = 0;
*value = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
return PCIBIOS_SUCCESSFUL;
}
/*
* We don't do error checks by callling clear_master_aborts() b/c the
* assumption is that the caller did a read first to make sure a device
* exists.
*/
int ixp2000_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where,
int size, u32 value)
{
u32 mask;
u32 *addr;
u32 temp;
mask = ~(bytemask[size] << ((where % 0x4) * 8));
addr = ixp2000_pci_config_addr(bus->number, devfn, where);
if (!addr)
return PCIBIOS_DEVICE_NOT_FOUND;
temp = (u32) (value) << ((where % 0x4) * 8);
*addr = (*addr & mask) | temp;
clear_master_aborts();
return PCIBIOS_SUCCESSFUL;
}
static struct pci_ops ixp2000_pci_ops = {
.read = ixp2000_pci_read_config,
.write = ixp2000_pci_write_config
};
struct pci_bus *ixp2000_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
{
return pci_scan_bus(sysdata->busnr, &ixp2000_pci_ops, sysdata);
}
int ixp2000_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
volatile u32 temp;
unsigned long flags;
pci_master_aborts = 1;
local_irq_save(flags);
temp = *(IXP2000_PCI_CONTROL);
if (temp & ((1 << 8) | (1 << 5))) {
ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
}
temp = *(IXP2000_PCI_CMDSTAT);
if (temp & (1 << 29)) {
while (temp & (1 << 29)) {
ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
temp = *(IXP2000_PCI_CMDSTAT);
}
}
local_irq_restore(flags);
/*
* If it was an imprecise abort, then we need to correct the
* return address to be _after_ the instruction.
*/
if (fsr & (1 << 10))
regs->ARM_pc += 4;
return 0;
}
int
clear_master_aborts(void)
{
volatile u32 temp;
unsigned long flags;
local_irq_save(flags);
temp = *(IXP2000_PCI_CONTROL);
if (temp & ((1 << 8) | (1 << 5))) {
ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
}
temp = *(IXP2000_PCI_CMDSTAT);
if (temp & (1 << 29)) {
while (temp & (1 << 29)) {
ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
temp = *(IXP2000_PCI_CMDSTAT);
}
}
local_irq_restore(flags);
return 0;
}
void __init
ixp2000_pci_preinit(void)
{
#ifndef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
/*
* Configure the PCI unit to properly byteswap I/O transactions,
* and verify that it worked.
*/
ixp2000_reg_write(IXP2000_PCI_CONTROL,
(*IXP2000_PCI_CONTROL | PCI_CONTROL_IEE));
if ((*IXP2000_PCI_CONTROL & PCI_CONTROL_IEE) == 0)
panic("IXP2000: PCI I/O is broken on this ixp model, and "
"the needed workaround has not been configured in");
#endif
hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS,
"PCI config cycle to non-existent device");
}
/*
* IXP2000 systems often have large resource requirements, so we just
* use our own resource space.
*/
static struct resource ixp2000_pci_mem_space = {
.start = 0xe0000000,
.end = 0xffffffff,
.flags = IORESOURCE_MEM,
.name = "PCI Mem Space"
};
static struct resource ixp2000_pci_io_space = {
.start = 0x00010000,
.end = 0x0001ffff,
.flags = IORESOURCE_IO,
.name = "PCI I/O Space"
};
int ixp2000_pci_setup(int nr, struct pci_sys_data *sys)
{
if (nr >= 1)
return 0;
sys->resource[0] = &ixp2000_pci_io_space;
sys->resource[1] = &ixp2000_pci_mem_space;
sys->resource[2] = NULL;
return 1;
}
