xilinx_pci.c
/*
* PCI support for Xilinx plbv46_pci soft-core which can be used on
* Xilinx Virtex ML410 / ML510 boards.
*
* Copyright 2009 Roderick Colenbrander
* Copyright 2009 Secret Lab Technologies Ltd.
*
* The pci bridge fixup code was copied from ppc4xx_pci.c and was written
* by Benjamin Herrenschmidt.
* Copyright 2007 Ben. Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/pci.h>
#include <mm/mmu_decl.h>
#include <asm/io.h>
#include <asm/xilinx_pci.h>
#define XPLB_PCI_ADDR 0x10c
#define XPLB_PCI_DATA 0x110
#define XPLB_PCI_BUS 0x114
#define PCI_HOST_ENABLE_CMD PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY
static const struct of_device_id xilinx_pci_match[] = {
{ .compatible = "xlnx,plbv46-pci-1.03.a", },
{}
};
/**
* xilinx_pci_fixup_bridge - Block Xilinx PHB configuration.
*/
static void xilinx_pci_fixup_bridge(struct pci_dev *dev)
{
struct pci_controller *hose;
int i;
if (dev->devfn || dev->bus->self)
return;
hose = pci_bus_to_host(dev->bus);
if (!hose)
return;
if (!of_match_node(xilinx_pci_match, hose->dn))
return;
/* Hide the PCI host BARs from the kernel as their content doesn't
* fit well in the resource management
*/
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
dev->resource[i].start = 0;
dev->resource[i].end = 0;
dev->resource[i].flags = 0;
}
dev_info(&dev->dev, "Hiding Xilinx plb-pci host bridge resources %s\n",
pci_name(dev));
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, xilinx_pci_fixup_bridge);
/**
* xilinx_pci_exclude_device - Don't do config access for non-root bus
*
* This is a hack. Config access to any bus other than bus 0 does not
* currently work on the ML510 so we prevent it here.
*/
static int
xilinx_pci_exclude_device(struct pci_controller *hose, u_char bus, u8 devfn)
{
return (bus != 0);
}
/**
* xilinx_pci_init - Find and register a Xilinx PCI host bridge
*/
void __init xilinx_pci_init(void)
{
struct pci_controller *hose;
struct resource r;
void __iomem *pci_reg;
struct device_node *pci_node;
pci_node = of_find_matching_node(NULL, xilinx_pci_match);
if(!pci_node)
return;
if (of_address_to_resource(pci_node, 0, &r)) {
pr_err("xilinx-pci: cannot resolve base address\n");
return;
}
hose = pcibios_alloc_controller(pci_node);
if (!hose) {
pr_err("xilinx-pci: pcibios_alloc_controller() failed\n");
return;
}
/* Setup config space */
setup_indirect_pci(hose, r.start + XPLB_PCI_ADDR,
r.start + XPLB_PCI_DATA,
PPC_INDIRECT_TYPE_SET_CFG_TYPE);
/* According to the xilinx plbv46_pci documentation the soft-core starts
* a self-init when the bus master enable bit is set. Without this bit
* set the pci bus can't be scanned.
*/
early_write_config_word(hose, 0, 0, PCI_COMMAND, PCI_HOST_ENABLE_CMD);
/* Set the max latency timer to 255 */
early_write_config_byte(hose, 0, 0, PCI_LATENCY_TIMER, 0xff);
/* Set the max bus number to 255 */
pci_reg = of_iomap(pci_node, 0);
out_8(pci_reg + XPLB_PCI_BUS, 0xff);
iounmap(pci_reg);
/* Nothing past the root bridge is working right now. By default
* exclude config access to anything except bus 0 */
if (!ppc_md.pci_exclude_device)
ppc_md.pci_exclude_device = xilinx_pci_exclude_device;
/* Register the host bridge with the linux kernel! */
pci_process_bridge_OF_ranges(hose, pci_node, 1);
pr_info("xilinx-pci: Registered PCI host bridge\n");
}