/*
 * 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>
 *
 * SPDX-License-Identifier:     GPL-2.0
 */

#include <common.h>
#include <pci.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/soc.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 resource {
        u32 start;
        u32 end;
};

struct mvebu_pcie {
        struct pci_controller hose;
        char *name;
        void __iomem *base;
        void __iomem *membase;
        struct resource mem;
        void __iomem *iobase;
        u32 port;
        u32 lane;
        u32 lane_mask;
        pci_dev_t dev;
};

#define to_pcie(_hc)    container_of(_hc, struct mvebu_pcie, pci)

/*
 * MVEBU PCIe controller needs MEMORY and I/O BARs to be mapped
 * into SoCs address space. Each controller will map 32M 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   (32 << 20)

#if defined(CONFIG_ARMADA_38X)
#define PCIE_BASE(if)                                   \
        ((if) == 0 ?                                    \
         MVEBU_REG_PCIE0_BASE :                         \
         (MVEBU_REG_PCIE_BASE + 0x4000 * (if - 1)))

/*
 * On A38x MV6820 these PEX ports are supported:
 *  0 - Port 0.0
 *  1 - Port 1.0
 *  2 - Port 2.0
 *  3 - Port 3.0
 */
#define MAX_PEX 4
static struct mvebu_pcie pcie_bus[MAX_PEX];

static void mvebu_get_port_lane(struct mvebu_pcie *pcie, int pex_idx,
                                int *mem_target, int *mem_attr)
{
        u8 port[] = { 0, 1, 2, 3 };
        u8 lane[] = { 0, 0, 0, 0 };
        u8 target[] = { 8, 4, 4, 4 };
        u8 attr[] = { 0xe8, 0xe8, 0xd8, 0xb8 };

        pcie->port = port[pex_idx];
        pcie->lane = lane[pex_idx];
        *mem_target = target[pex_idx];
        *mem_attr = attr[pex_idx];
}
#else
#define PCIE_BASE(if)                                                   \
        ((if) < 8 ?                                                     \
         (MVEBU_REG_PCIE_BASE + ((if) / 4) * 0x40000 + ((if) % 4) * 0x4000) : \
         (MVEBU_REG_PCIE_BASE + 0x2000 + ((if) % 8) * 0x40000))

/*
 * On AXP MV78460 these PEX ports are supported:
 *  0 - Port 0.0
 *  1 - Port 0.1
 *  2 - Port 0.2
 *  3 - Port 0.3
 *  4 - Port 1.0
 *  5 - Port 1.1
 *  6 - Port 1.2
 *  7 - Port 1.3
 *  8 - Port 2.0
 *  9 - Port 3.0
 */
#define MAX_PEX 10
static struct mvebu_pcie pcie_bus[MAX_PEX];

static void mvebu_get_port_lane(struct mvebu_pcie *pcie, int pex_idx,
                                int *mem_target, int *mem_attr)
{
        u8 port[] = { 0, 0, 0, 0, 1, 1, 1, 1, 2, 3 };
        u8 lane[] = { 0, 1, 2, 3, 0, 1, 2, 3, 0, 0 };
        u8 target[] = { 4, 4, 4, 4, 8, 8, 8, 8, 4, 8 };
        u8 attr[] = { 0xe8, 0xd8, 0xb8, 0x78,
                      0xe8, 0xd8, 0xb8, 0x78,
                      0xf8, 0xf8 };

        pcie->port = port[pex_idx];
        pcie->lane = lane[pex_idx];
        *mem_target = target[pex_idx];
        *mem_attr = attr[pex_idx];
}
#endif

static int mvebu_pex_unit_is_x4(int pex_idx)
{
        int pex_unit = pex_idx < 9 ? pex_idx >> 2 : 3;
        u32 mask = (0x0f << (pex_unit * 8));

        return (readl(COMPHY_REFCLK_ALIGNMENT) & mask) == mask;
}

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_read_config_dword(struct pci_controller *hose,
                pci_dev_t dev, int offset, u32 *val)
{
        struct mvebu_pcie *pcie = hose_to_pcie(hose);
        int local_bus = PCI_BUS(pcie->dev);
        int local_dev = PCI_DEV(pcie->dev);
        u32 reg;

        /* Only allow one other device besides the local one on the local bus */
        if (PCI_BUS(dev) == local_bus && PCI_DEV(dev) != local_dev) {
                if (local_dev == 0 && PCI_DEV(dev) != 1) {
                        /*
                         * If local dev is 0, the first other dev can
                         * only be 1
                         */
                        *val = 0xffffffff;
                        return 1;
                } else if (local_dev != 0 && PCI_DEV(dev) != 0) {
                        /*
                         * If local dev is not 0, the first other dev can
                         * only be 0
                         */
                        *val = 0xffffffff;
                        return 1;
                }
        }

        /* write address */
        reg = PCIE_CONF_ADDR(dev, offset);
        writel(reg, pcie->base + PCIE_CONF_ADDR_OFF);
        *val = readl(pcie->base + PCIE_CONF_DATA_OFF);

        return 0;
}

static int mvebu_pcie_write_config_dword(struct pci_controller *hose,
                pci_dev_t dev, int offset, u32 val)
{
        struct mvebu_pcie *pcie = hose_to_pcie(hose);
        int local_bus = PCI_BUS(pcie->dev);
        int local_dev = PCI_DEV(pcie->dev);

        /* Only allow one other device besides the local one on the local bus */
        if (PCI_BUS(dev) == local_bus && PCI_DEV(dev) != local_dev) {
                if (local_dev == 0 && PCI_DEV(dev) != 1) {
                        /*
                         * If local dev is 0, the first other dev can
                         * only be 1
                         */
                        return 1;
                } else if (local_dev != 0 && PCI_DEV(dev) != 0) {
                        /*
                         * If local dev is not 0, the first other dev can
                         * only be 0
                         */
                        return 1;
                }
        }

        writel(PCIE_CONF_ADDR(dev, offset), pcie->base + PCIE_CONF_ADDR_OFF);
        writel(val, 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));
}

void pci_init_board(void)
{
        int mem_target, mem_attr, i;
        int bus = 0;
        u32 reg;
        u32 soc_ctrl = readl(MVEBU_SYSTEM_REG_BASE + 0x4);

        /* Check SoC Control Power State */
        debug("%s: SoC Control %08x, 0en %01lx, 1en %01lx, 2en %01lx\n",
              __func__, soc_ctrl, SELECT(soc_ctrl, 0), SELECT(soc_ctrl, 1),
              SELECT(soc_ctrl, 2));

        for (i = 0; i < MAX_PEX; i++) {
                struct mvebu_pcie *pcie = &pcie_bus[i];
                struct pci_controller *hose = &pcie->hose;

                /* Get port number, lane number and memory target / attr */
                mvebu_get_port_lane(pcie, i, &mem_target, &mem_attr);

                /* Don't read at all from pci registers if port power is down */
                if (SELECT(soc_ctrl, pcie->port) == 0) {
                        if (pcie->lane == 0)
                                debug("%s: skipping port %d\n", __func__, pcie->port);
                        continue;
                }

                pcie->base = (void __iomem *)PCIE_BASE(i);

                /* Check link and skip ports that have no link */
                if (!mvebu_pcie_link_up(pcie)) {
                        debug("%s: PCIe %d.%d - down\n", __func__,
                              pcie->port, pcie->lane);
                        continue;
                }
                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));

                mvebu_pcie_set_local_bus_nr(pcie, bus);
                mvebu_pcie_set_local_dev_nr(pcie, 0);
                pcie->dev = PCI_BDF(bus, 0, 0);

                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(mem_target, 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);
                }

                /* 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_MASTER;
                reg |= BIT(10);         /* disable interrupts */
                writel(reg, pcie->base + PCIE_CMD_OFF);

                /* Setup U-Boot PCI Controller */
                hose->first_busno = 0;
                hose->current_busno = bus;

                /* 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);
                hose->region_count = 2;

                pci_set_ops(hose,
                            pci_hose_read_config_byte_via_dword,
                            pci_hose_read_config_word_via_dword,
                            mvebu_pcie_read_config_dword,
                            pci_hose_write_config_byte_via_dword,
                            pci_hose_write_config_word_via_dword,
                            mvebu_pcie_write_config_dword);
                pci_register_hose(hose);

                hose->last_busno = pci_hose_scan(hose);

                /* 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));

                bus = hose->last_busno + 1;

                /* need to skip more for X4 links, otherwise scan will hang */
                if (mvebu_soc_family() == MVEBU_SOC_AXP) {
                        if (mvebu_pex_unit_is_x4(i))
                                i += 3;
                }
        }
}