root/arch/arm/mach-mv78xx0/pcie.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * arch/arm/mach-mv78xx0/pcie.c
 *
 * PCIe functions for Marvell MV78xx0 SoCs
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/mbus.h>
#include <video/vga.h>
#include <asm/irq.h>
#include <asm/mach/pci.h>
#include <plat/pcie.h>
#include "mv78xx0.h"
#include "common.h"

#define MV78XX0_MBUS_PCIE_MEM_TARGET(port, lane) ((port) ? 8 : 4)
#define MV78XX0_MBUS_PCIE_MEM_ATTR(port, lane)   (0xf8 & ~(0x10 << (lane)))
#define MV78XX0_MBUS_PCIE_IO_TARGET(port, lane)  ((port) ? 8 : 4)
#define MV78XX0_MBUS_PCIE_IO_ATTR(port, lane)    (0xf0 & ~(0x10 << (lane)))

struct pcie_port {
        u8                      maj;
        u8                      min;
        u8                      root_bus_nr;
        void __iomem            *base;
        spinlock_t              conf_lock;
        char                    mem_space_name[20];
        struct resource         res;
};

static struct pcie_port pcie_port[8];
static int num_pcie_ports;
static struct resource pcie_io_space;

void __init mv78xx0_pcie_id(u32 *dev, u32 *rev)
{
        *dev = orion_pcie_dev_id(PCIE00_VIRT_BASE);
        *rev = orion_pcie_rev(PCIE00_VIRT_BASE);
}

u32 pcie_port_size[8] = {
        0,
        0x20000000,
        0x10000000,
        0x10000000,
        0x08000000,
        0x08000000,
        0x08000000,
        0x04000000,
};

static void __init mv78xx0_pcie_preinit(void)
{
        int i;
        u32 size_each;
        u32 start;

        pcie_io_space.name = "PCIe I/O Space";
        pcie_io_space.start = MV78XX0_PCIE_IO_PHYS_BASE(0);
        pcie_io_space.end =
                MV78XX0_PCIE_IO_PHYS_BASE(0) + MV78XX0_PCIE_IO_SIZE * 8 - 1;
        pcie_io_space.flags = IORESOURCE_MEM;
        if (request_resource(&iomem_resource, &pcie_io_space))
                panic("can't allocate PCIe I/O space");

        if (num_pcie_ports > 7)
                panic("invalid number of PCIe ports");

        size_each = pcie_port_size[num_pcie_ports];

        start = MV78XX0_PCIE_MEM_PHYS_BASE;
        for (i = 0; i < num_pcie_ports; i++) {
                struct pcie_port *pp = pcie_port + i;

                snprintf(pp->mem_space_name, sizeof(pp->mem_space_name),
                        "PCIe %d.%d MEM", pp->maj, pp->min);
                pp->mem_space_name[sizeof(pp->mem_space_name) - 1] = 0;
                pp->res.name = pp->mem_space_name;
                pp->res.flags = IORESOURCE_MEM;
                pp->res.start = start;
                pp->res.end = start + size_each - 1;
                start += size_each;

                if (request_resource(&iomem_resource, &pp->res))
                        panic("can't allocate PCIe MEM sub-space");

                mvebu_mbus_add_window_by_id(MV78XX0_MBUS_PCIE_MEM_TARGET(pp->maj, pp->min),
                                            MV78XX0_MBUS_PCIE_MEM_ATTR(pp->maj, pp->min),
                                            pp->res.start, resource_size(&pp->res));
                mvebu_mbus_add_window_remap_by_id(MV78XX0_MBUS_PCIE_IO_TARGET(pp->maj, pp->min),
                                                  MV78XX0_MBUS_PCIE_IO_ATTR(pp->maj, pp->min),
                                                  i * SZ_64K, SZ_64K, 0);
        }
}

static int __init mv78xx0_pcie_setup(int nr, struct pci_sys_data *sys)
{
        struct pcie_port *pp;
        struct resource realio;

        if (nr >= num_pcie_ports)
                return 0;

        pp = &pcie_port[nr];
        sys->private_data = pp;
        pp->root_bus_nr = sys->busnr;

        /*
         * Generic PCIe unit setup.
         */
        orion_pcie_set_local_bus_nr(pp->base, sys->busnr);
        orion_pcie_setup(pp->base);

        realio.start = nr * SZ_64K;
        realio.end = realio.start + SZ_64K - 1;
        pci_remap_iospace(&realio, MV78XX0_PCIE_IO_PHYS_BASE(nr));

        pci_add_resource_offset(&sys->resources, &pp->res, sys->mem_offset);

        return 1;
}

static int pcie_valid_config(struct pcie_port *pp, int bus, int dev)
{
        /*
         * Don't go out when trying to access nonexisting devices
         * on the local bus.
         */
        if (bus == pp->root_bus_nr && dev > 1)
                return 0;

        return 1;
}

static int pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
                        int size, u32 *val)
{
        struct pci_sys_data *sys = bus->sysdata;
        struct pcie_port *pp = sys->private_data;
        unsigned long flags;
        int ret;

        if (pcie_valid_config(pp, bus->number, PCI_SLOT(devfn)) == 0) {
                *val = 0xffffffff;
                return PCIBIOS_DEVICE_NOT_FOUND;
        }

        spin_lock_irqsave(&pp->conf_lock, flags);
        ret = orion_pcie_rd_conf(pp->base, bus, devfn, where, size, val);
        spin_unlock_irqrestore(&pp->conf_lock, flags);

        return ret;
}

static int pcie_wr_conf(struct pci_bus *bus, u32 devfn,
                        int where, int size, u32 val)
{
        struct pci_sys_data *sys = bus->sysdata;
        struct pcie_port *pp = sys->private_data;
        unsigned long flags;
        int ret;

        if (pcie_valid_config(pp, bus->number, PCI_SLOT(devfn)) == 0)
                return PCIBIOS_DEVICE_NOT_FOUND;

        spin_lock_irqsave(&pp->conf_lock, flags);
        ret = orion_pcie_wr_conf(pp->base, bus, devfn, where, size, val);
        spin_unlock_irqrestore(&pp->conf_lock, flags);

        return ret;
}

static struct pci_ops pcie_ops = {
        .read = pcie_rd_conf,
        .write = pcie_wr_conf,
};

/*
 * The root complex has a hardwired class of PCI_CLASS_MEMORY_OTHER, when it
 * is operating as a root complex this needs to be switched to
 * PCI_CLASS_BRIDGE_HOST or Linux will errantly try to process the BAR's on
 * the device. Decoding setup is handled by the orion code.
 */
static void rc_pci_fixup(struct pci_dev *dev)
{
        if (dev->bus->parent == NULL && dev->devfn == 0) {
                struct resource *r;

                dev->class &= 0xff;
                dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
                pci_dev_for_each_resource(dev, r) {
                        r->start = 0;
                        r->end   = 0;
                        r->flags = 0;
                }
        }
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MARVELL, PCI_ANY_ID, rc_pci_fixup);

static int __init mv78xx0_pcie_scan_bus(int nr, struct pci_host_bridge *bridge)
{
        struct pci_sys_data *sys = pci_host_bridge_priv(bridge);

        if (nr >= num_pcie_ports) {
                BUG();
                return -EINVAL;
        }

        list_splice_init(&sys->resources, &bridge->windows);
        bridge->dev.parent = NULL;
        bridge->sysdata = sys;
        bridge->busnr = sys->busnr;
        bridge->ops = &pcie_ops;

        return pci_scan_root_bus_bridge(bridge);
}

static int __init mv78xx0_pcie_map_irq(const struct pci_dev *dev, u8 slot,
        u8 pin)
{
        struct pci_sys_data *sys = dev->bus->sysdata;
        struct pcie_port *pp = sys->private_data;

        return IRQ_MV78XX0_PCIE_00 + (pp->maj << 2) + pp->min;
}

static struct hw_pci mv78xx0_pci __initdata = {
        .nr_controllers = 8,
        .preinit        = mv78xx0_pcie_preinit,
        .setup          = mv78xx0_pcie_setup,
        .scan           = mv78xx0_pcie_scan_bus,
        .map_irq        = mv78xx0_pcie_map_irq,
};

static void __init add_pcie_port(int maj, int min, void __iomem *base)
{
        printk(KERN_INFO "MV78xx0 PCIe port %d.%d: ", maj, min);

        if (orion_pcie_link_up(base)) {
                struct pcie_port *pp = &pcie_port[num_pcie_ports++];

                printk("link up\n");

                pp->maj = maj;
                pp->min = min;
                pp->root_bus_nr = -1;
                pp->base = base;
                spin_lock_init(&pp->conf_lock);
                memset(&pp->res, 0, sizeof(pp->res));
        } else {
                printk("link down, ignoring\n");
        }
}

void __init mv78xx0_pcie_init(int init_port0, int init_port1)
{
        vga_base = MV78XX0_PCIE_MEM_PHYS_BASE;

        if (init_port0) {
                add_pcie_port(0, 0, PCIE00_VIRT_BASE);
                if (!orion_pcie_x4_mode(PCIE00_VIRT_BASE)) {
                        add_pcie_port(0, 1, PCIE01_VIRT_BASE);
                        add_pcie_port(0, 2, PCIE02_VIRT_BASE);
                        add_pcie_port(0, 3, PCIE03_VIRT_BASE);
                }
        }

        if (init_port1) {
                add_pcie_port(1, 0, PCIE10_VIRT_BASE);
                if (!orion_pcie_x4_mode((void __iomem *)PCIE10_VIRT_BASE)) {
                        add_pcie_port(1, 1, PCIE11_VIRT_BASE);
                        add_pcie_port(1, 2, PCIE12_VIRT_BASE);
                        add_pcie_port(1, 3, PCIE13_VIRT_BASE);
                }
        }

        pci_common_init(&mv78xx0_pci);
}