blob: 6d4ef0101ef68274c963b26580493751952b7e8b [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Synopsys DesignWare PCIe host controller driver
*
* Copyright (C) 2013 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* Author: Jingoo Han <jg1.han@samsung.com>
*/
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/pci_regs.h>
#include <linux/platform_device.h>
#include "../../pci.h"
#include "pcie-designware.h"
static struct pci_ops dw_pcie_ops;
static int dw_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
u32 *val)
{
struct dw_pcie *pci;
if (pp->ops->rd_own_conf)
return pp->ops->rd_own_conf(pp, where, size, val);
pci = to_dw_pcie_from_pp(pp);
return dw_pcie_read(pci->dbi_base + where, size, val);
}
static int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size,
u32 val)
{
struct dw_pcie *pci;
if (pp->ops->wr_own_conf)
return pp->ops->wr_own_conf(pp, where, size, val);
pci = to_dw_pcie_from_pp(pp);
return dw_pcie_write(pci->dbi_base + where, size, val);
}
static void dw_msi_ack_irq(struct irq_data *d)
{
irq_chip_ack_parent(d);
}
static void dw_msi_mask_irq(struct irq_data *d)
{
pci_msi_mask_irq(d);
irq_chip_mask_parent(d);
}
static void dw_msi_unmask_irq(struct irq_data *d)
{
pci_msi_unmask_irq(d);
irq_chip_unmask_parent(d);
}
static struct irq_chip dw_pcie_msi_irq_chip = {
.name = "PCI-MSI",
.irq_ack = dw_msi_ack_irq,
.irq_mask = dw_msi_mask_irq,
.irq_unmask = dw_msi_unmask_irq,
};
static struct msi_domain_info dw_pcie_msi_domain_info = {
.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
.chip = &dw_pcie_msi_irq_chip,
};
/* MSI int handler */
irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
{
int i, pos, irq;
unsigned long val;
u32 status, num_ctrls;
irqreturn_t ret = IRQ_NONE;
num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
for (i = 0; i < num_ctrls; i++) {
dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS +
(i * MSI_REG_CTRL_BLOCK_SIZE),
4, &status);
if (!status)
continue;
ret = IRQ_HANDLED;
val = status;
pos = 0;
while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL,
pos)) != MAX_MSI_IRQS_PER_CTRL) {
irq = irq_find_mapping(pp->irq_domain,
(i * MAX_MSI_IRQS_PER_CTRL) +
pos);
generic_handle_irq(irq);
pos++;
}
}
return ret;
}
/* Chained MSI interrupt service routine */
static void dw_chained_msi_isr(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct pcie_port *pp;
chained_irq_enter(chip, desc);
pp = irq_desc_get_handler_data(desc);
dw_handle_msi_irq(pp);
chained_irq_exit(chip, desc);
}
static void dw_pci_setup_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
struct pcie_port *pp = irq_data_get_irq_chip_data(data);
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
u64 msi_target;
if (pp->ops->get_msi_addr)
msi_target = pp->ops->get_msi_addr(pp);
else
msi_target = (u64)pp->msi_data;
msg->address_lo = lower_32_bits(msi_target);
msg->address_hi = upper_32_bits(msi_target);
if (pp->ops->get_msi_data)
msg->data = pp->ops->get_msi_data(pp, data->hwirq);
else
msg->data = data->hwirq;
dev_dbg(pci->dev, "msi#%d address_hi %#x address_lo %#x\n",
(int)data->hwirq, msg->address_hi, msg->address_lo);
}
static int dw_pci_msi_set_affinity(struct irq_data *irq_data,
const struct cpumask *mask, bool force)
{
return -EINVAL;
}
static void dw_pci_bottom_mask(struct irq_data *data)
{
struct pcie_port *pp = irq_data_get_irq_chip_data(data);
unsigned int res, bit, ctrl;
unsigned long flags;
raw_spin_lock_irqsave(&pp->lock, flags);
if (pp->ops->msi_clear_irq) {
pp->ops->msi_clear_irq(pp, data->hwirq);
} else {
ctrl = data->hwirq / MAX_MSI_IRQS_PER_CTRL;
res = ctrl * MSI_REG_CTRL_BLOCK_SIZE;
bit = data->hwirq % MAX_MSI_IRQS_PER_CTRL;
pp->irq_status[ctrl] &= ~(1 << bit);
dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_MASK + res, 4,
~pp->irq_status[ctrl]);
}
raw_spin_unlock_irqrestore(&pp->lock, flags);
}
static void dw_pci_bottom_unmask(struct irq_data *data)
{
struct pcie_port *pp = irq_data_get_irq_chip_data(data);
unsigned int res, bit, ctrl;
unsigned long flags;
raw_spin_lock_irqsave(&pp->lock, flags);
if (pp->ops->msi_set_irq) {
pp->ops->msi_set_irq(pp, data->hwirq);
} else {
ctrl = data->hwirq / MAX_MSI_IRQS_PER_CTRL;
res = ctrl * MSI_REG_CTRL_BLOCK_SIZE;
bit = data->hwirq % MAX_MSI_IRQS_PER_CTRL;
pp->irq_status[ctrl] |= 1 << bit;
dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_MASK + res, 4,
~pp->irq_status[ctrl]);
}
raw_spin_unlock_irqrestore(&pp->lock, flags);
}
static void dw_pci_bottom_ack(struct irq_data *d)
{
struct pcie_port *pp = irq_data_get_irq_chip_data(d);
unsigned int res, bit, ctrl;
unsigned long flags;
ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL;
res = ctrl * MSI_REG_CTRL_BLOCK_SIZE;
bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL;
raw_spin_lock_irqsave(&pp->lock, flags);
dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + res, 4, 1 << bit);
if (pp->ops->msi_irq_ack)
pp->ops->msi_irq_ack(d->hwirq, pp);
raw_spin_unlock_irqrestore(&pp->lock, flags);
}
static struct irq_chip dw_pci_msi_bottom_irq_chip = {
.name = "DWPCI-MSI",
.irq_ack = dw_pci_bottom_ack,
.irq_compose_msi_msg = dw_pci_setup_msi_msg,
.irq_set_affinity = dw_pci_msi_set_affinity,
.irq_mask = dw_pci_bottom_mask,
.irq_unmask = dw_pci_bottom_unmask,
};
static int dw_pcie_irq_domain_alloc(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs,
void *args)
{
struct pcie_port *pp = domain->host_data;
unsigned long flags;
u32 i;
int bit;
raw_spin_lock_irqsave(&pp->lock, flags);
bit = bitmap_find_free_region(pp->msi_irq_in_use, pp->num_vectors,
order_base_2(nr_irqs));
raw_spin_unlock_irqrestore(&pp->lock, flags);
if (bit < 0)
return -ENOSPC;
for (i = 0; i < nr_irqs; i++)
irq_domain_set_info(domain, virq + i, bit + i,
&dw_pci_msi_bottom_irq_chip,
pp, handle_edge_irq,
NULL, NULL);
return 0;
}
static void dw_pcie_irq_domain_free(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs)
{
struct irq_data *data = irq_domain_get_irq_data(domain, virq);
struct pcie_port *pp = irq_data_get_irq_chip_data(data);
unsigned long flags;
raw_spin_lock_irqsave(&pp->lock, flags);
bitmap_release_region(pp->msi_irq_in_use, data->hwirq,
order_base_2(nr_irqs));
raw_spin_unlock_irqrestore(&pp->lock, flags);
}
static const struct irq_domain_ops dw_pcie_msi_domain_ops = {
.alloc = dw_pcie_irq_domain_alloc,
.free = dw_pcie_irq_domain_free,
};
int dw_pcie_allocate_domains(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct fwnode_handle *fwnode = of_node_to_fwnode(pci->dev->of_node);
pp->irq_domain = irq_domain_create_linear(fwnode, pp->num_vectors,
&dw_pcie_msi_domain_ops, pp);
if (!pp->irq_domain) {
dev_err(pci->dev, "Failed to create IRQ domain\n");
return -ENOMEM;
}
pp->msi_domain = pci_msi_create_irq_domain(fwnode,
&dw_pcie_msi_domain_info,
pp->irq_domain);
if (!pp->msi_domain) {
dev_err(pci->dev, "Failed to create MSI domain\n");
irq_domain_remove(pp->irq_domain);
return -ENOMEM;
}
return 0;
}
void dw_pcie_free_msi(struct pcie_port *pp)
{
irq_set_chained_handler(pp->msi_irq, NULL);
irq_set_handler_data(pp->msi_irq, NULL);
irq_domain_remove(pp->msi_domain);
irq_domain_remove(pp->irq_domain);
if (pp->msi_page)
__free_page(pp->msi_page);
}
void dw_pcie_msi_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct device *dev = pci->dev;
u64 msi_target;
pp->msi_page = alloc_page(GFP_KERNEL);
pp->msi_data = dma_map_page(dev, pp->msi_page, 0, PAGE_SIZE,
DMA_FROM_DEVICE);
if (dma_mapping_error(dev, pp->msi_data)) {
dev_err(dev, "Failed to map MSI data\n");
__free_page(pp->msi_page);
pp->msi_page = NULL;
return;
}
msi_target = (u64)pp->msi_data;
/* Program the msi_data */
dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_LO, 4,
lower_32_bits(msi_target));
dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_HI, 4,
upper_32_bits(msi_target));
}
int dw_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct device *dev = pci->dev;
struct device_node *np = dev->of_node;
struct platform_device *pdev = to_platform_device(dev);
struct resource_entry *win, *tmp;
struct pci_bus *bus, *child;
struct pci_host_bridge *bridge;
struct resource *cfg_res;
int ret;
raw_spin_lock_init(&pci->pp.lock);
cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
if (cfg_res) {
pp->cfg0_size = resource_size(cfg_res) >> 1;
pp->cfg1_size = resource_size(cfg_res) >> 1;
pp->cfg0_base = cfg_res->start;
pp->cfg1_base = cfg_res->start + pp->cfg0_size;
} else if (!pp->va_cfg0_base) {
dev_err(dev, "Missing *config* reg space\n");
}
bridge = devm_pci_alloc_host_bridge(dev, 0);
if (!bridge)
return -ENOMEM;
ret = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff,
&bridge->windows, &pp->io_base);
if (ret)
return ret;
ret = devm_request_pci_bus_resources(dev, &bridge->windows);
if (ret)
return ret;
/* Get the I/O and memory ranges from DT */
resource_list_for_each_entry_safe(win, tmp, &bridge->windows) {
switch (resource_type(win->res)) {
case IORESOURCE_IO:
ret = devm_pci_remap_iospace(dev, win->res,
pp->io_base);
if (ret) {
dev_warn(dev, "Error %d: failed to map resource %pR\n",
ret, win->res);
resource_list_destroy_entry(win);
} else {
pp->io = win->res;
pp->io->name = "I/O";
pp->io_size = resource_size(pp->io);
pp->io_bus_addr = pp->io->start - win->offset;
}
break;
case IORESOURCE_MEM:
pp->mem = win->res;
pp->mem->name = "MEM";
pp->mem_size = resource_size(pp->mem);
pp->mem_bus_addr = pp->mem->start - win->offset;
break;
case 0:
pp->cfg = win->res;
pp->cfg0_size = resource_size(pp->cfg) >> 1;
pp->cfg1_size = resource_size(pp->cfg) >> 1;
pp->cfg0_base = pp->cfg->start;
pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
break;
case IORESOURCE_BUS:
pp->busn = win->res;
break;
}
}
if (!pci->dbi_base) {
pci->dbi_base = devm_pci_remap_cfgspace(dev,
pp->cfg->start,
resource_size(pp->cfg));
if (!pci->dbi_base) {
dev_err(dev, "Error with ioremap\n");
return -ENOMEM;
}
}
pp->mem_base = pp->mem->start;
if (!pp->va_cfg0_base) {
pp->va_cfg0_base = devm_pci_remap_cfgspace(dev,
pp->cfg0_base, pp->cfg0_size);
if (!pp->va_cfg0_base) {
dev_err(dev, "Error with ioremap in function\n");
return -ENOMEM;
}
}
if (!pp->va_cfg1_base) {
pp->va_cfg1_base = devm_pci_remap_cfgspace(dev,
pp->cfg1_base,
pp->cfg1_size);
if (!pp->va_cfg1_base) {
dev_err(dev, "Error with ioremap\n");
return -ENOMEM;
}
}
ret = of_property_read_u32(np, "num-viewport", &pci->num_viewport);
if (ret)
pci->num_viewport = 2;
if (pci_msi_enabled()) {
/*
* If a specific SoC driver needs to change the
* default number of vectors, it needs to implement
* the set_num_vectors callback.
*/
if (!pp->ops->set_num_vectors) {
pp->num_vectors = MSI_DEF_NUM_VECTORS;
} else {
pp->ops->set_num_vectors(pp);
if (pp->num_vectors > MAX_MSI_IRQS ||
pp->num_vectors == 0) {
dev_err(dev,
"Invalid number of vectors\n");
return -EINVAL;
}
}
if (!pp->ops->msi_host_init) {
ret = dw_pcie_allocate_domains(pp);
if (ret)
return ret;
if (pp->msi_irq)
irq_set_chained_handler_and_data(pp->msi_irq,
dw_chained_msi_isr,
pp);
} else {
ret = pp->ops->msi_host_init(pp);
if (ret < 0)
return ret;
}
}
if (pp->ops->host_init) {
ret = pp->ops->host_init(pp);
if (ret)
goto err_free_msi;
}
pp->root_bus_nr = pp->busn->start;
bridge->dev.parent = dev;
bridge->sysdata = pp;
bridge->busnr = pp->root_bus_nr;
bridge->ops = &dw_pcie_ops;
bridge->map_irq = of_irq_parse_and_map_pci;
bridge->swizzle_irq = pci_common_swizzle;
ret = pci_scan_root_bus_bridge(bridge);
if (ret)
goto err_free_msi;
bus = bridge->bus;
if (pp->ops->scan_bus)
pp->ops->scan_bus(pp);
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child);
pci_bus_add_devices(bus);
return 0;
err_free_msi:
if (pci_msi_enabled() && !pp->ops->msi_host_init)
dw_pcie_free_msi(pp);
return ret;
}
static int dw_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
u32 devfn, int where, int size, u32 *val)
{
int ret, type;
u32 busdev, cfg_size;
u64 cpu_addr;
void __iomem *va_cfg_base;
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
if (pp->ops->rd_other_conf)
return pp->ops->rd_other_conf(pp, bus, devfn, where, size, val);
busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
PCIE_ATU_FUNC(PCI_FUNC(devfn));
if (bus->parent->number == pp->root_bus_nr) {
type = PCIE_ATU_TYPE_CFG0;
cpu_addr = pp->cfg0_base;
cfg_size = pp->cfg0_size;
va_cfg_base = pp->va_cfg0_base;
} else {
type = PCIE_ATU_TYPE_CFG1;
cpu_addr = pp->cfg1_base;
cfg_size = pp->cfg1_size;
va_cfg_base = pp->va_cfg1_base;
}
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
type, cpu_addr,
busdev, cfg_size);
ret = dw_pcie_read(va_cfg_base + where, size, val);
if (pci->num_viewport <= 2)
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
PCIE_ATU_TYPE_IO, pp->io_base,
pp->io_bus_addr, pp->io_size);
return ret;
}
static int dw_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
u32 devfn, int where, int size, u32 val)
{
int ret, type;
u32 busdev, cfg_size;
u64 cpu_addr;
void __iomem *va_cfg_base;
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
if (pp->ops->wr_other_conf)
return pp->ops->wr_other_conf(pp, bus, devfn, where, size, val);
busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
PCIE_ATU_FUNC(PCI_FUNC(devfn));
if (bus->parent->number == pp->root_bus_nr) {
type = PCIE_ATU_TYPE_CFG0;
cpu_addr = pp->cfg0_base;
cfg_size = pp->cfg0_size;
va_cfg_base = pp->va_cfg0_base;
} else {
type = PCIE_ATU_TYPE_CFG1;
cpu_addr = pp->cfg1_base;
cfg_size = pp->cfg1_size;
va_cfg_base = pp->va_cfg1_base;
}
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
type, cpu_addr,
busdev, cfg_size);
ret = dw_pcie_write(va_cfg_base + where, size, val);
if (pci->num_viewport <= 2)
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
PCIE_ATU_TYPE_IO, pp->io_base,
pp->io_bus_addr, pp->io_size);
return ret;
}
static int dw_pcie_valid_device(struct pcie_port *pp, struct pci_bus *bus,
int dev)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
/* If there is no link, then there is no device */
if (bus->number != pp->root_bus_nr) {
if (!dw_pcie_link_up(pci))
return 0;
}
/* Access only one slot on each root port */
if (bus->number == pp->root_bus_nr && dev > 0)
return 0;
return 1;
}
static int dw_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
int size, u32 *val)
{
struct pcie_port *pp = bus->sysdata;
if (!dw_pcie_valid_device(pp, bus, PCI_SLOT(devfn))) {
*val = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
if (bus->number == pp->root_bus_nr)
return dw_pcie_rd_own_conf(pp, where, size, val);
return dw_pcie_rd_other_conf(pp, bus, devfn, where, size, val);
}
static int dw_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
int where, int size, u32 val)
{
struct pcie_port *pp = bus->sysdata;
if (!dw_pcie_valid_device(pp, bus, PCI_SLOT(devfn)))
return PCIBIOS_DEVICE_NOT_FOUND;
if (bus->number == pp->root_bus_nr)
return dw_pcie_wr_own_conf(pp, where, size, val);
return dw_pcie_wr_other_conf(pp, bus, devfn, where, size, val);
}
static struct pci_ops dw_pcie_ops = {
.read = dw_pcie_rd_conf,
.write = dw_pcie_wr_conf,
};
static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci)
{
u32 val;
val = dw_pcie_readl_dbi(pci, PCIE_ATU_VIEWPORT);
if (val == 0xffffffff)
return 1;
return 0;
}
void dw_pcie_setup_rc(struct pcie_port *pp)
{
u32 val, ctrl, num_ctrls;
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
dw_pcie_setup(pci);
num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
/* Initialize IRQ Status array */
for (ctrl = 0; ctrl < num_ctrls; ctrl++) {
dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_MASK +
(ctrl * MSI_REG_CTRL_BLOCK_SIZE),
4, ~0);
dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE +
(ctrl * MSI_REG_CTRL_BLOCK_SIZE),
4, ~0);
pp->irq_status[ctrl] = 0;
}
/* Setup RC BARs */
dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0x00000004);
dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
/* Setup interrupt pins */
dw_pcie_dbi_ro_wr_en(pci);
val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE);
val &= 0xffff00ff;
val |= 0x00000100;
dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val);
dw_pcie_dbi_ro_wr_dis(pci);
/* Setup bus numbers */
val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
val &= 0xff000000;
val |= 0x00ff0100;
dw_pcie_writel_dbi(pci, PCI_PRIMARY_BUS, val);
/* Setup command register */
val = dw_pcie_readl_dbi(pci, PCI_COMMAND);
val &= 0xffff0000;
val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
PCI_COMMAND_MASTER | PCI_COMMAND_SERR;
dw_pcie_writel_dbi(pci, PCI_COMMAND, val);
/*
* If the platform provides ->rd_other_conf, it means the platform
* uses its own address translation component rather than ATU, so
* we should not program the ATU here.
*/
if (!pp->ops->rd_other_conf) {
/* Get iATU unroll support */
pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci);
dev_dbg(pci->dev, "iATU unroll: %s\n",
pci->iatu_unroll_enabled ? "enabled" : "disabled");
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX0,
PCIE_ATU_TYPE_MEM, pp->mem_base,
pp->mem_bus_addr, pp->mem_size);
if (pci->num_viewport > 2)
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX2,
PCIE_ATU_TYPE_IO, pp->io_base,
pp->io_bus_addr, pp->io_size);
}
dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
/* Enable write permission for the DBI read-only register */
dw_pcie_dbi_ro_wr_en(pci);
/* Program correct class for RC */
dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);
/* Better disable write permission right after the update */
dw_pcie_dbi_ro_wr_dis(pci);
dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val);
val |= PORT_LOGIC_SPEED_CHANGE;
dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val);
}