kernel_optimize_test/arch/mips/pci/ops-lantiq.c
John Crispin e47d488935 MIPS: Lantiq: Add PCI controller support.
The Lantiq family of SoCs have a EBU (External Bus Unit). This patch adds
the driver that allows us to use the EBU as a PCI controller. In order for
PCI to work the EBU is set to endianess swap all the data. In addition we
need to make use of SWAP_IO_SPACE for device->host DMA to work.

The clock of the PCI works in several modes (internal/external). If this
is not configured correctly the SoC will hang.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2250/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-05-19 09:55:42 +01:00

117 lines
2.9 KiB
C

/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* Copyright (C) 2010 John Crispin <blogic@openwrt.org>
*/
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <asm/addrspace.h>
#include <linux/vmalloc.h>
#include <lantiq_soc.h>
#include "pci-lantiq.h"
#define LTQ_PCI_CFG_BUSNUM_SHF 16
#define LTQ_PCI_CFG_DEVNUM_SHF 11
#define LTQ_PCI_CFG_FUNNUM_SHF 8
#define PCI_ACCESS_READ 0
#define PCI_ACCESS_WRITE 1
static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
unsigned int devfn, unsigned int where, u32 *data)
{
unsigned long cfg_base;
unsigned long flags;
u32 temp;
/* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
SoC itself */
if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
|| ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
return 1;
spin_lock_irqsave(&ebu_lock, flags);
cfg_base = (unsigned long) ltq_pci_mapped_cfg;
cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);
/* Perform access */
if (access_type == PCI_ACCESS_WRITE) {
ltq_w32(swab32(*data), ((u32 *)cfg_base));
} else {
*data = ltq_r32(((u32 *)(cfg_base)));
*data = swab32(*data);
}
wmb();
/* clean possible Master abort */
cfg_base = (unsigned long) ltq_pci_mapped_cfg;
cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
temp = ltq_r32(((u32 *)(cfg_base)));
temp = swab32(temp);
cfg_base = (unsigned long) ltq_pci_mapped_cfg;
cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
ltq_w32(temp, ((u32 *)cfg_base));
spin_unlock_irqrestore(&ebu_lock, flags);
if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
return 1;
return 0;
}
int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
u32 data = 0;
if (ltq_pci_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;
}
int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
u32 data = 0;
if (size == 4) {
data = val;
} else {
if (ltq_pci_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 (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
return PCIBIOS_DEVICE_NOT_FOUND;
return PCIBIOS_SUCCESSFUL;
}