/*
* Copyright (C) 2001,2002,2005 Broadcom Corporation
* Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
* BCM1480/1455-specific HT support (looking like PCI)
*
* This module provides the glue between Linux's PCI subsystem
* and the hardware. We basically provide glue for accessing
* configuration space, and set up the translation for I/O
* space accesses.
*
* To access configuration space, we use ioremap. In the 32-bit
* kernel, this consumes either 4 or 8 page table pages, and 16MB of
* kernel mapped memory. Hopefully neither of these should be a huge
* problem.
*
*/
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_scd.h>
#include <asm/sibyte/board.h>
#include <asm/io.h>
/*
* Macros for calculating offsets into config space given a device
* structure or dev/fun/reg
*/
#define CFGOFFSET(bus, devfn, where) (((bus)<<16)+((devfn)<<8)+(where))
#define CFGADDR(bus, devfn, where) CFGOFFSET((bus)->number, (devfn), where)
static void *ht_cfg_space;
#define PCI_BUS_ENABLED 1
#define PCI_DEVICE_MODE 2
static int bcm1480ht_bus_status = 0;
#define PCI_BRIDGE_DEVICE 0
#define HT_BRIDGE_DEVICE 1
/*
* HT's level-sensitive interrupts require EOI, which is generated
* through a 4MB memory-mapped region
*/
unsigned long ht_eoi_space;
/*
* Read/write 32-bit values in config space.
*/
static inline u32 READCFG32(u32 addr)
{
return *(u32 *)(ht_cfg_space + (addr&~3));
}
static inline void WRITECFG32(u32 addr, u32 data)
{
*(u32 *)(ht_cfg_space + (addr & ~3)) = data;
}
/*
* Some checks before doing config cycles:
* In PCI Device Mode, hide everything on bus 0 except the LDT host
* bridge. Otherwise, access is controlled by bridge MasterEn bits.
*/
static int bcm1480ht_can_access(struct pci_bus *bus, int devfn)
{
u32 devno;
if (!(bcm1480ht_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
return 0;
if (bus->number == 0) {
devno = PCI_SLOT(devfn);
if (bcm1480ht_bus_status & PCI_DEVICE_MODE)
return 0;
}
return 1;
}
/*
* Read/write access functions for various sizes of values
* in config space. Return all 1's for disallowed accesses
* for a kludgy but adequate simulation of master aborts.
*/
static int bcm1480ht_pcibios_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 * val)
{
u32 data = 0;
if ((size == 2) && (where & 1))
return PCIBIOS_BAD_REGISTER_NUMBER;
else if ((size == 4) && (where & 3))
return PCIBIOS_BAD_REGISTER_NUMBER;
if (bcm1480ht_can_access(bus, devfn))
data = READCFG32(CFGADDR(bus, devfn, where));
else
data = 0xFFFFFFFF;
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 bcm1480ht_pcibios_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
u32 cfgaddr = CFGADDR(bus, devfn, where);
u32 data = 0;
if ((size == 2) && (where & 1))
return PCIBIOS_BAD_REGISTER_NUMBER;
else if ((size == 4) && (where & 3))
return PCIBIOS_BAD_REGISTER_NUMBER;
if (!bcm1480ht_can_access(bus, devfn))
return PCIBIOS_BAD_REGISTER_NUMBER;
data = READCFG32(cfgaddr);
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));
else
data = val;
WRITECFG32(cfgaddr, data);
return PCIBIOS_SUCCESSFUL;
}
static int bcm1480ht_pcibios_get_busno(void)
{
return 0;
}
struct pci_ops bcm1480ht_pci_ops = {
.read = bcm1480ht_pcibios_read,
.write = bcm1480ht_pcibios_write,
};
static struct resource bcm1480ht_mem_resource = {
.name = "BCM1480 HT MEM",
.start = A_BCM1480_PHYS_HT_MEM_MATCH_BYTES,
.end = A_BCM1480_PHYS_HT_MEM_MATCH_BYTES + 0x1fffffffUL,
.flags = IORESOURCE_MEM,
};
static struct resource bcm1480ht_io_resource = {
.name = "BCM1480 HT I/O",
.start = 0x00000000UL,
.end = 0x01ffffffUL,
.flags = IORESOURCE_IO,
};
struct pci_controller bcm1480ht_controller = {
.pci_ops = &bcm1480ht_pci_ops,
.mem_resource = &bcm1480ht_mem_resource,
.io_resource = &bcm1480ht_io_resource,
.index = 1,
.get_busno = bcm1480ht_pcibios_get_busno,
};
static int __init bcm1480ht_pcibios_init(void)
{
uint32_t cmdreg;
ht_cfg_space = ioremap(A_BCM1480_PHYS_HT_CFG_MATCH_BITS, 16*1024*1024);
/*
* See if the PCI bus has been configured by the firmware.
*/
cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
PCI_COMMAND));
if (!(cmdreg & PCI_COMMAND_MASTER)) {
printk("HT: Skipping HT probe. Bus is not initialized.\n");
iounmap(ht_cfg_space);
return 1; /* XXX */
}
bcm1480ht_bus_status |= PCI_BUS_ENABLED;
ht_eoi_space = (unsigned long)
ioremap(A_BCM1480_PHYS_HT_SPECIAL_MATCH_BYTES,
4 * 1024 * 1024);
register_pci_controller(&bcm1480ht_controller);
return 0;
}
arch_initcall(bcm1480ht_pcibios_init);
