// SPDX-License-Identifier: GPL-2.0
/*
 * PCIe driver for Marvell MVEBU SoCs
 *
 * Based on Barebox drivers/pci/pci-mvebu.c
 *
 * Ported to U-Boot by:
 * Anton Schubert <anton.schubert@gmx.de>
 * Stefan Roese <sr@denx.de>
 */

#include <common.h>
#include <dm.h>
#include <log.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/of_access.h>
#include <pci.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/soc.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/mbus.h>

DECLARE_GLOBAL_DATA_PTR;

/* PCIe unit register offsets */
#define SELECT(x, n)                    ((x >> n) & 1UL)

#define PCIE_DEV_ID_OFF                 0x0000
#define PCIE_CMD_OFF                    0x0004
#define PCIE_DEV_REV_OFF                0x0008
#define  PCIE_BAR_LO_OFF(n)             (0x0010 + ((n) << 3))
#define  PCIE_BAR_HI_OFF(n)             (0x0014 + ((n) << 3))
#define PCIE_CAPAB_OFF                  0x0060
#define PCIE_CTRL_STAT_OFF              0x0068
#define PCIE_HEADER_LOG_4_OFF           0x0128
#define  PCIE_BAR_CTRL_OFF(n)           (0x1804 + (((n) - 1) * 4))
#define  PCIE_WIN04_CTRL_OFF(n)         (0x1820 + ((n) << 4))
#define  PCIE_WIN04_BASE_OFF(n)         (0x1824 + ((n) << 4))
#define  PCIE_WIN04_REMAP_OFF(n)        (0x182c + ((n) << 4))
#define PCIE_WIN5_CTRL_OFF              0x1880
#define PCIE_WIN5_BASE_OFF              0x1884
#define PCIE_WIN5_REMAP_OFF             0x188c
#define PCIE_CONF_ADDR_OFF              0x18f8
#define  PCIE_CONF_ADDR_EN              BIT(31)
#define  PCIE_CONF_REG(r)               ((((r) & 0xf00) << 16) | ((r) & 0xfc))
#define  PCIE_CONF_BUS(b)               (((b) & 0xff) << 16)
#define  PCIE_CONF_DEV(d)               (((d) & 0x1f) << 11)
#define  PCIE_CONF_FUNC(f)              (((f) & 0x7) << 8)
#define  PCIE_CONF_ADDR(dev, reg) \
        (PCIE_CONF_BUS(PCI_BUS(dev)) | PCIE_CONF_DEV(PCI_DEV(dev))    | \
         PCIE_CONF_FUNC(PCI_FUNC(dev)) | PCIE_CONF_REG(reg) | \
         PCIE_CONF_ADDR_EN)
#define PCIE_CONF_DATA_OFF              0x18fc
#define PCIE_MASK_OFF                   0x1910
#define  PCIE_MASK_ENABLE_INTS          (0xf << 24)
#define PCIE_CTRL_OFF                   0x1a00
#define  PCIE_CTRL_X1_MODE              BIT(0)
#define PCIE_STAT_OFF                   0x1a04
#define  PCIE_STAT_BUS                  (0xff << 8)
#define  PCIE_STAT_DEV                  (0x1f << 16)
#define  PCIE_STAT_LINK_DOWN            BIT(0)
#define PCIE_DEBUG_CTRL                 0x1a60
#define  PCIE_DEBUG_SOFT_RESET          BIT(20)

struct mvebu_pcie {
        struct pci_controller hose;
        void __iomem *base;
        void __iomem *membase;
        struct resource mem;
        void __iomem *iobase;
        struct resource io;
        u32 port;
        u32 lane;
        int devfn;
        u32 lane_mask;
        int first_busno;
        int local_dev;
        char name[16];
        unsigned int mem_target;
        unsigned int mem_attr;
        unsigned int io_target;
        unsigned int io_attr;
};

/*
 * MVEBU PCIe controller needs MEMORY and I/O BARs to be mapped
 * into SoCs address space. Each controller will map 128M of MEM
 * and 64K of I/O space when registered.
 */
static void __iomem *mvebu_pcie_membase = (void __iomem *)MBUS_PCI_MEM_BASE;
#define PCIE_MEM_SIZE   (128 << 20)
static void __iomem *mvebu_pcie_iobase = (void __iomem *)MBUS_PCI_IO_BASE;

static inline bool mvebu_pcie_link_up(struct mvebu_pcie *pcie)
{
        u32 val;
        val = readl(pcie->base + PCIE_STAT_OFF);
        return !(val & PCIE_STAT_LINK_DOWN);
}

static void mvebu_pcie_set_local_bus_nr(struct mvebu_pcie *pcie, int busno)
{
        u32 stat;

        stat = readl(pcie->base + PCIE_STAT_OFF);
        stat &= ~PCIE_STAT_BUS;
        stat |= busno << 8;
        writel(stat, pcie->base + PCIE_STAT_OFF);
}

static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie *pcie, int devno)
{
        u32 stat;

        stat = readl(pcie->base + PCIE_STAT_OFF);
        stat &= ~PCIE_STAT_DEV;
        stat |= devno << 16;
        writel(stat, pcie->base + PCIE_STAT_OFF);
}

static int mvebu_pcie_get_local_bus_nr(struct mvebu_pcie *pcie)
{
        u32 stat;

        stat = readl(pcie->base + PCIE_STAT_OFF);
        return (stat & PCIE_STAT_BUS) >> 8;
}

static int mvebu_pcie_get_local_dev_nr(struct mvebu_pcie *pcie)
{
        u32 stat;

        stat = readl(pcie->base + PCIE_STAT_OFF);
        return (stat & PCIE_STAT_DEV) >> 16;
}

static inline struct mvebu_pcie *hose_to_pcie(struct pci_controller *hose)
{
        return container_of(hose, struct mvebu_pcie, hose);
}

static int mvebu_pcie_valid_addr(struct mvebu_pcie *pcie, pci_dev_t bdf)
{
        /*
         * There are two devices visible on local bus:
         *   * on slot configured by function mvebu_pcie_set_local_dev_nr()
         *     (by default this register is set to 0) there is a
         *     "Marvell Memory controller", which isn't useful in root complex
         *     mode,
         *   * on all other slots the real PCIe card connected to the PCIe slot.
         *
         * We therefore allow access only to the real PCIe card.
         */
        if (PCI_BUS(bdf) == pcie->first_busno &&
            PCI_DEV(bdf) != !pcie->local_dev)
                return 0;

        return 1;
}

static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
                                  uint offset, ulong *valuep,
                                  enum pci_size_t size)
{
        struct mvebu_pcie *pcie = dev_get_plat(bus);
        u32 data;

        debug("PCIE CFG read: (b,d,f)=(%2d,%2d,%2d) ",
              PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));

        if (!mvebu_pcie_valid_addr(pcie, bdf)) {
                debug("- out of range\n");
                *valuep = pci_get_ff(size);
                return 0;
        }

        /* write address */
        writel(PCIE_CONF_ADDR(bdf, offset), pcie->base + PCIE_CONF_ADDR_OFF);

        /* read data */
        data = readl(pcie->base + PCIE_CONF_DATA_OFF);
        debug("(addr,size,val)=(0x%04x, %d, 0x%08x)\n", offset, size, data);
        *valuep = pci_conv_32_to_size(data, offset, size);

        return 0;
}

static int mvebu_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
                                   uint offset, ulong value,
                                   enum pci_size_t size)
{
        struct mvebu_pcie *pcie = dev_get_plat(bus);
        u32 data;

        debug("PCIE CFG write: (b,d,f)=(%2d,%2d,%2d) ",
              PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
        debug("(addr,size,val)=(0x%04x, %d, 0x%08lx)\n", offset, size, value);

        if (!mvebu_pcie_valid_addr(pcie, bdf)) {
                debug("- out of range\n");
                return 0;
        }

        /* write address */
        writel(PCIE_CONF_ADDR(bdf, offset), pcie->base + PCIE_CONF_ADDR_OFF);

        /* write data */
        data = pci_conv_size_to_32(0, value, offset, size);
        writel(data, pcie->base + PCIE_CONF_DATA_OFF);

        return 0;
}

/*
 * Setup PCIE BARs and Address Decode Wins:
 * BAR[0,2] -> disabled, BAR[1] -> covers all DRAM banks
 * WIN[0-3] -> DRAM bank[0-3]
 */
static void mvebu_pcie_setup_wins(struct mvebu_pcie *pcie)
{
        const struct mbus_dram_target_info *dram = mvebu_mbus_dram_info();
        u32 size;
        int i;

        /* First, disable and clear BARs and windows. */
        for (i = 1; i < 3; i++) {
                writel(0, pcie->base + PCIE_BAR_CTRL_OFF(i));
                writel(0, pcie->base + PCIE_BAR_LO_OFF(i));
                writel(0, pcie->base + PCIE_BAR_HI_OFF(i));
        }

        for (i = 0; i < 5; i++) {
                writel(0, pcie->base + PCIE_WIN04_CTRL_OFF(i));
                writel(0, pcie->base + PCIE_WIN04_BASE_OFF(i));
                writel(0, pcie->base + PCIE_WIN04_REMAP_OFF(i));
        }

        writel(0, pcie->base + PCIE_WIN5_CTRL_OFF);
        writel(0, pcie->base + PCIE_WIN5_BASE_OFF);
        writel(0, pcie->base + PCIE_WIN5_REMAP_OFF);

        /* Setup windows for DDR banks. Count total DDR size on the fly. */
        size = 0;
        for (i = 0; i < dram->num_cs; i++) {
                const struct mbus_dram_window *cs = dram->cs + i;

                writel(cs->base & 0xffff0000,
                       pcie->base + PCIE_WIN04_BASE_OFF(i));
                writel(0, pcie->base + PCIE_WIN04_REMAP_OFF(i));
                writel(((cs->size - 1) & 0xffff0000) |
                       (cs->mbus_attr << 8) |
                       (dram->mbus_dram_target_id << 4) | 1,
                       pcie->base + PCIE_WIN04_CTRL_OFF(i));

                size += cs->size;
        }

        /* Round up 'size' to the nearest power of two. */
        if ((size & (size - 1)) != 0)
                size = 1 << fls(size);

        /* Setup BAR[1] to all DRAM banks. */
        writel(dram->cs[0].base | 0xc, pcie->base + PCIE_BAR_LO_OFF(1));
        writel(0, pcie->base + PCIE_BAR_HI_OFF(1));
        writel(((size - 1) & 0xffff0000) | 0x1,
               pcie->base + PCIE_BAR_CTRL_OFF(1));
}

static int mvebu_pcie_probe(struct udevice *dev)
{
        struct mvebu_pcie *pcie = dev_get_plat(dev);
        struct udevice *ctlr = pci_get_controller(dev);
        struct pci_controller *hose = dev_get_uclass_priv(ctlr);
        int bus = dev_seq(dev);
        u32 reg;

        debug("%s: PCIe %d.%d - up, base %08x\n", __func__,
              pcie->port, pcie->lane, (u32)pcie->base);

        /* Read Id info and local bus/dev */
        debug("direct conf read %08x, local bus %d, local dev %d\n",
              readl(pcie->base), mvebu_pcie_get_local_bus_nr(pcie),
              mvebu_pcie_get_local_dev_nr(pcie));

        pcie->first_busno = bus;
        pcie->local_dev = 1;

        mvebu_pcie_set_local_bus_nr(pcie, bus);
        mvebu_pcie_set_local_dev_nr(pcie, pcie->local_dev);

        pcie->mem.start = (u32)mvebu_pcie_membase;
        pcie->mem.end = pcie->mem.start + PCIE_MEM_SIZE - 1;
        mvebu_pcie_membase += PCIE_MEM_SIZE;

        if (mvebu_mbus_add_window_by_id(pcie->mem_target, pcie->mem_attr,
                                        (phys_addr_t)pcie->mem.start,
                                        PCIE_MEM_SIZE)) {
                printf("PCIe unable to add mbus window for mem at %08x+%08x\n",
                       (u32)pcie->mem.start, PCIE_MEM_SIZE);
        }

        pcie->io.start = (u32)mvebu_pcie_iobase;
        pcie->io.end = pcie->io.start + MBUS_PCI_IO_SIZE - 1;
        mvebu_pcie_iobase += MBUS_PCI_IO_SIZE;

        if (mvebu_mbus_add_window_by_id(pcie->io_target, pcie->io_attr,
                                        (phys_addr_t)pcie->io.start,
                                        MBUS_PCI_IO_SIZE)) {
                printf("PCIe unable to add mbus window for IO at %08x+%08x\n",
                       (u32)pcie->io.start, MBUS_PCI_IO_SIZE);
        }

        /* Setup windows and configure host bridge */
        mvebu_pcie_setup_wins(pcie);

        /* Master + slave enable. */
        reg = readl(pcie->base + PCIE_CMD_OFF);
        reg |= PCI_COMMAND_MEMORY;
        reg |= PCI_COMMAND_IO;
        reg |= PCI_COMMAND_MASTER;
        reg |= BIT(10);         /* disable interrupts */
        writel(reg, pcie->base + PCIE_CMD_OFF);

        /* PCI memory space */
        pci_set_region(hose->regions + 0, pcie->mem.start,
                       pcie->mem.start, PCIE_MEM_SIZE, PCI_REGION_MEM);
        pci_set_region(hose->regions + 1,
                       0, 0,
                       gd->ram_size,
                       PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
        pci_set_region(hose->regions + 2, pcie->io.start,
                       pcie->io.start, MBUS_PCI_IO_SIZE, PCI_REGION_IO);
        hose->region_count = 3;

        /* Set BAR0 to internal registers */
        writel(SOC_REGS_PHY_BASE, pcie->base + PCIE_BAR_LO_OFF(0));
        writel(0, pcie->base + PCIE_BAR_HI_OFF(0));

        return 0;
}

static int mvebu_pcie_port_parse_dt(ofnode node, struct mvebu_pcie *pcie)
{
        const u32 *addr;
        int len;

        addr = ofnode_get_property(node, "assigned-addresses", &len);
        if (!addr) {
                pr_err("property \"assigned-addresses\" not found");
                return -FDT_ERR_NOTFOUND;
        }

        pcie->base = (void *)(fdt32_to_cpu(addr[2]) + SOC_REGS_PHY_BASE);

        return 0;
}

#define DT_FLAGS_TO_TYPE(flags)       (((flags) >> 24) & 0x03)
#define    DT_TYPE_IO                 0x1
#define    DT_TYPE_MEM32              0x2
#define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
#define DT_CPUADDR_TO_ATTR(cpuaddr)   (((cpuaddr) >> 48) & 0xFF)

static int mvebu_get_tgt_attr(ofnode node, int devfn,
                              unsigned long type,
                              unsigned int *tgt,
                              unsigned int *attr)
{
        const int na = 3, ns = 2;
        const __be32 *range;
        int rlen, nranges, rangesz, pna, i;

        *tgt = -1;
        *attr = -1;

        range = ofnode_get_property(node, "ranges", &rlen);
        if (!range)
                return -EINVAL;

        /*
         * Linux uses of_n_addr_cells() to get the number of address cells
         * here. Currently this function is only available in U-Boot when
         * CONFIG_OF_LIVE is enabled. Until this is enabled for MVEBU in
         * general, lets't hardcode the "pna" value in the U-Boot code.
         */
        pna = 2; /* hardcoded for now because of lack of of_n_addr_cells() */
        rangesz = pna + na + ns;
        nranges = rlen / sizeof(__be32) / rangesz;

        for (i = 0; i < nranges; i++, range += rangesz) {
                u32 flags = of_read_number(range, 1);
                u32 slot = of_read_number(range + 1, 1);
                u64 cpuaddr = of_read_number(range + na, pna);
                unsigned long rtype;

                if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
                        rtype = IORESOURCE_IO;
                else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
                        rtype = IORESOURCE_MEM;
                else
                        continue;

                /*
                 * The Linux code used PCI_SLOT() here, which expects devfn
                 * in bits 7..0. PCI_DEV() in U-Boot is similar to PCI_SLOT(),
                 * only expects devfn in 15..8, where its saved in this driver.
                 */
                if (slot == PCI_DEV(devfn) && type == rtype) {
                        *tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
                        *attr = DT_CPUADDR_TO_ATTR(cpuaddr);
                        return 0;
                }
        }

        return -ENOENT;
}

static int mvebu_pcie_of_to_plat(struct udevice *dev)
{
        struct mvebu_pcie *pcie = dev_get_plat(dev);
        int ret = 0;

        /* Get port number, lane number and memory target / attr */
        if (ofnode_read_u32(dev_ofnode(dev), "marvell,pcie-port",
                            &pcie->port)) {
                ret = -ENODEV;
                goto err;
        }

        if (ofnode_read_u32(dev_ofnode(dev), "marvell,pcie-lane", &pcie->lane))
                pcie->lane = 0;

        sprintf(pcie->name, "pcie%d.%d", pcie->port, pcie->lane);

        /* pci_get_devfn() returns devfn in bits 15..8, see PCI_DEV usage */
        pcie->devfn = pci_get_devfn(dev);
        if (pcie->devfn < 0) {
                ret = -ENODEV;
                goto err;
        }

        ret = mvebu_get_tgt_attr(dev_ofnode(dev->parent), pcie->devfn,
                                 IORESOURCE_MEM,
                                 &pcie->mem_target, &pcie->mem_attr);
        if (ret < 0) {
                printf("%s: cannot get tgt/attr for mem window\n", pcie->name);
                goto err;
        }

        ret = mvebu_get_tgt_attr(dev_ofnode(dev->parent), pcie->devfn,
                                 IORESOURCE_IO,
                                 &pcie->io_target, &pcie->io_attr);
        if (ret < 0) {
                printf("%s: cannot get tgt/attr for IO window\n", pcie->name);
                goto err;
        }

        /* Parse PCIe controller register base from DT */
        ret = mvebu_pcie_port_parse_dt(dev_ofnode(dev), pcie);
        if (ret < 0)
                goto err;

        /* Check link and skip ports that have no link */
        if (!mvebu_pcie_link_up(pcie)) {
                debug("%s: %s - down\n", __func__, pcie->name);
                ret = -ENODEV;
                goto err;
        }

        return 0;

err:
        return ret;
}

static const struct dm_pci_ops mvebu_pcie_ops = {
        .read_config    = mvebu_pcie_read_config,
        .write_config   = mvebu_pcie_write_config,
};

static struct driver pcie_mvebu_drv = {
        .name                   = "pcie_mvebu",
        .id                     = UCLASS_PCI,
        .ops                    = &mvebu_pcie_ops,
        .probe                  = mvebu_pcie_probe,
        .of_to_plat     = mvebu_pcie_of_to_plat,
        .plat_auto      = sizeof(struct mvebu_pcie),
};

/*
 * Use a MISC device to bind the n instances (child nodes) of the
 * PCIe base controller in UCLASS_PCI.
 */
static int mvebu_pcie_bind(struct udevice *parent)
{
        struct mvebu_pcie *pcie;
        struct uclass_driver *drv;
        struct udevice *dev;
        ofnode subnode;

        /* Lookup eth driver */
        drv = lists_uclass_lookup(UCLASS_PCI);
        if (!drv) {
                puts("Cannot find PCI driver\n");
                return -ENOENT;
        }

        ofnode_for_each_subnode(subnode, dev_ofnode(parent)) {
                if (!ofnode_is_available(subnode))
                        continue;

                pcie = calloc(1, sizeof(*pcie));
                if (!pcie)
                        return -ENOMEM;

                /* Create child device UCLASS_PCI and bind it */
                device_bind(parent, &pcie_mvebu_drv, pcie->name, pcie, subnode,
                            &dev);
        }

        return 0;
}

static const struct udevice_id mvebu_pcie_ids[] = {
        { .compatible = "marvell,armada-xp-pcie" },
        { .compatible = "marvell,armada-370-pcie" },
        { }
};

U_BOOT_DRIVER(pcie_mvebu_base) = {
        .name                   = "pcie_mvebu_base",
        .id                     = UCLASS_MISC,
        .of_match               = mvebu_pcie_ids,
        .bind                   = mvebu_pcie_bind,
};