blob: 50a8e1d6f70a188a24aada2050892f4f2f03e4c1 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Loongson PCI Host Controller Driver
*
* Copyright (C) 2020 Jiaxun Yang <jiaxun.yang@flygoat.com>
*/
#include <linux/of_device.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include "../pci.h"
/* Device IDs */
#define DEV_PCIE_PORT_0 0x7a09
#define DEV_PCIE_PORT_1 0x7a19
#define DEV_PCIE_PORT_2 0x7a29
#define DEV_LS2K_APB 0x7a02
#define DEV_LS7A_CONF 0x7a10
#define DEV_LS7A_LPC 0x7a0c
#define FLAG_CFG0 BIT(0)
#define FLAG_CFG1 BIT(1)
#define FLAG_DEV_FIX BIT(2)
struct loongson_pci {
void __iomem *cfg0_base;
void __iomem *cfg1_base;
struct platform_device *pdev;
u32 flags;
};
/* Fixup wrong class code in PCIe bridges */
static void bridge_class_quirk(struct pci_dev *dev)
{
dev->class = PCI_CLASS_BRIDGE_PCI_NORMAL;
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
DEV_PCIE_PORT_0, bridge_class_quirk);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
DEV_PCIE_PORT_1, bridge_class_quirk);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
DEV_PCIE_PORT_2, bridge_class_quirk);
static void system_bus_quirk(struct pci_dev *pdev)
{
/*
* The address space consumed by these devices is outside the
* resources of the host bridge.
*/
pdev->mmio_always_on = 1;
pdev->non_compliant_bars = 1;
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
DEV_LS2K_APB, system_bus_quirk);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
DEV_LS7A_CONF, system_bus_quirk);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON,
DEV_LS7A_LPC, system_bus_quirk);
static void loongson_mrrs_quirk(struct pci_dev *dev)
{
struct pci_bus *bus = dev->bus;
struct pci_dev *bridge;
static const struct pci_device_id bridge_devids[] = {
{ PCI_VDEVICE(LOONGSON, DEV_PCIE_PORT_0) },
{ PCI_VDEVICE(LOONGSON, DEV_PCIE_PORT_1) },
{ PCI_VDEVICE(LOONGSON, DEV_PCIE_PORT_2) },
{ 0, },
};
/* look for the matching bridge */
while (!pci_is_root_bus(bus)) {
bridge = bus->self;
bus = bus->parent;
/*
* Some Loongson PCIe ports have a h/w limitation of
* 256 bytes maximum read request size. They can't handle
* anything larger than this. So force this limit on
* any devices attached under these ports.
*/
if (pci_match_id(bridge_devids, bridge)) {
if (pcie_get_readrq(dev) > 256) {
pci_info(dev, "limiting MRRS to 256\n");
pcie_set_readrq(dev, 256);
}
break;
}
}
}
DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, loongson_mrrs_quirk);
static void __iomem *cfg1_map(struct loongson_pci *priv, int bus,
unsigned int devfn, int where)
{
unsigned long addroff = 0x0;
if (bus != 0)
addroff |= BIT(28); /* Type 1 Access */
addroff |= (where & 0xff) | ((where & 0xf00) << 16);
addroff |= (bus << 16) | (devfn << 8);
return priv->cfg1_base + addroff;
}
static void __iomem *cfg0_map(struct loongson_pci *priv, int bus,
unsigned int devfn, int where)
{
unsigned long addroff = 0x0;
if (bus != 0)
addroff |= BIT(24); /* Type 1 Access */
addroff |= (bus << 16) | (devfn << 8) | where;
return priv->cfg0_base + addroff;
}
static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devfn,
int where)
{
unsigned char busnum = bus->number;
struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
struct loongson_pci *priv = pci_host_bridge_priv(bridge);
/*
* Do not read more than one device on the bus other than
* the host bus. For our hardware the root bus is always bus 0.
*/
if (priv->flags & FLAG_DEV_FIX && busnum != 0 &&
PCI_SLOT(devfn) > 0)
return NULL;
/* CFG0 can only access standard space */
if (where < PCI_CFG_SPACE_SIZE && priv->cfg0_base)
return cfg0_map(priv, busnum, devfn, where);
/* CFG1 can access extended space */
if (where < PCI_CFG_SPACE_EXP_SIZE && priv->cfg1_base)
return cfg1_map(priv, busnum, devfn, where);
return NULL;
}
static int loongson_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
int irq;
u8 val;
irq = of_irq_parse_and_map_pci(dev, slot, pin);
if (irq > 0)
return irq;
/* Care i8259 legacy systems */
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &val);
/* i8259 only have 15 IRQs */
if (val > 15)
return 0;
return val;
}
/* H/w only accept 32-bit PCI operations */
static struct pci_ops loongson_pci_ops = {
.map_bus = pci_loongson_map_bus,
.read = pci_generic_config_read32,
.write = pci_generic_config_write32,
};
static const struct of_device_id loongson_pci_of_match[] = {
{ .compatible = "loongson,ls2k-pci",
.data = (void *)(FLAG_CFG0 | FLAG_CFG1 | FLAG_DEV_FIX), },
{ .compatible = "loongson,ls7a-pci",
.data = (void *)(FLAG_CFG0 | FLAG_CFG1 | FLAG_DEV_FIX), },
{ .compatible = "loongson,rs780e-pci",
.data = (void *)(FLAG_CFG0), },
{}
};
static int loongson_pci_probe(struct platform_device *pdev)
{
struct loongson_pci *priv;
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node;
struct pci_host_bridge *bridge;
struct resource *regs;
if (!node)
return -ENODEV;
bridge = devm_pci_alloc_host_bridge(dev, sizeof(*priv));
if (!bridge)
return -ENODEV;
priv = pci_host_bridge_priv(bridge);
priv->pdev = pdev;
priv->flags = (unsigned long)of_device_get_match_data(dev);
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!regs) {
dev_err(dev, "missing mem resources for cfg0\n");
return -EINVAL;
}
priv->cfg0_base = devm_pci_remap_cfg_resource(dev, regs);
if (IS_ERR(priv->cfg0_base))
return PTR_ERR(priv->cfg0_base);
/* CFG1 is optional */
if (priv->flags & FLAG_CFG1) {
regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!regs)
dev_info(dev, "missing mem resource for cfg1\n");
else {
priv->cfg1_base = devm_pci_remap_cfg_resource(dev, regs);
if (IS_ERR(priv->cfg1_base))
priv->cfg1_base = NULL;
}
}
bridge->sysdata = priv;
bridge->ops = &loongson_pci_ops;
bridge->map_irq = loongson_map_irq;
return pci_host_probe(bridge);
}
static struct platform_driver loongson_pci_driver = {
.driver = {
.name = "loongson-pci",
.of_match_table = loongson_pci_of_match,
},
.probe = loongson_pci_probe,
};
builtin_platform_driver(loongson_pci_driver);