/*
 * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
 *
 * Intel Platform Controller Hub EG20T (codename Topcliff) GMAC Driver
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <asm/io.h>
#include <pci.h>
#include <miiphy.h>
#include "pch_gbe.h"

#if !defined(CONFIG_PHYLIB)
# error "PCH Gigabit Ethernet driver requires PHYLIB - missing CONFIG_PHYLIB"
#endif

static struct pci_device_id supported[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TCF_GBE) },
        { }
};

static void pch_gbe_mac_read(struct pch_gbe_regs *mac_regs, u8 *addr)
{
        u32 macid_hi, macid_lo;

        macid_hi = readl(&mac_regs->mac_adr[0].high);
        macid_lo = readl(&mac_regs->mac_adr[0].low) & 0xffff;
        debug("pch_gbe: macid_hi %#x macid_lo %#x\n", macid_hi, macid_lo);

        addr[0] = (u8)(macid_hi & 0xff);
        addr[1] = (u8)((macid_hi >> 8) & 0xff);
        addr[2] = (u8)((macid_hi >> 16) & 0xff);
        addr[3] = (u8)((macid_hi >> 24) & 0xff);
        addr[4] = (u8)(macid_lo & 0xff);
        addr[5] = (u8)((macid_lo >> 8) & 0xff);
}

static int pch_gbe_mac_write(struct pch_gbe_regs *mac_regs, u8 *addr)
{
        u32 macid_hi, macid_lo;
        ulong start;

        macid_hi = addr[0] + (addr[1] << 8) + (addr[2] << 16) + (addr[3] << 24);
        macid_lo = addr[4] + (addr[5] << 8);

        writel(macid_hi, &mac_regs->mac_adr[0].high);
        writel(macid_lo, &mac_regs->mac_adr[0].low);
        writel(0xfffe, &mac_regs->addr_mask);

        start = get_timer(0);
        while (get_timer(start) < PCH_GBE_TIMEOUT) {
                if (!(readl(&mac_regs->addr_mask) & PCH_GBE_BUSY))
                        return 0;

                udelay(10);
        }

        return -ETIME;
}

static int pch_gbe_reset(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct eth_pdata *plat = dev_get_platdata(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;
        ulong start;

        priv->rx_idx = 0;
        priv->tx_idx = 0;

        writel(PCH_GBE_ALL_RST, &mac_regs->reset);

        /*
         * Configure the MAC to RGMII mode after reset
         *
         * For some unknown reason, we must do the configuration here right
         * after resetting the whole MAC, otherwise the reset bit in the RESET
         * register will never be cleared by the hardware. And there is another
         * way of having the same magic, that is to configure the MODE register
         * to have the MAC work in MII/GMII mode, which is how current Linux
         * pch_gbe driver does. Since anyway we need program the MAC to RGMII
         * mode in the driver, we just do it here.
         *
         * Note: this behavior is not documented in the hardware manual.
         */
        writel(PCH_GBE_RGMII_MODE_RGMII | PCH_GBE_CHIP_TYPE_INTERNAL,
               &mac_regs->rgmii_ctrl);

        start = get_timer(0);
        while (get_timer(start) < PCH_GBE_TIMEOUT) {
                if (!(readl(&mac_regs->reset) & PCH_GBE_ALL_RST)) {
                        /*
                         * Soft reset clears hardware MAC address registers,
                         * so we have to reload MAC address here in order to
                         * make linux pch_gbe driver happy.
                         */
                        return pch_gbe_mac_write(mac_regs, plat->enetaddr);
                }

                udelay(10);
        }

        debug("pch_gbe: reset timeout\n");
        return -ETIME;
}

static void pch_gbe_rx_descs_init(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;
        struct pch_gbe_rx_desc *rx_desc = &priv->rx_desc[0];
        int i;

        memset(rx_desc, 0, sizeof(struct pch_gbe_rx_desc) * PCH_GBE_DESC_NUM);
        for (i = 0; i < PCH_GBE_DESC_NUM; i++)
                rx_desc->buffer_addr = dm_pci_phys_to_mem(priv->dev,
                        (ulong)(priv->rx_buff[i]));

        writel(dm_pci_phys_to_mem(priv->dev, (ulong)rx_desc),
               &mac_regs->rx_dsc_base);
        writel(sizeof(struct pch_gbe_rx_desc) * (PCH_GBE_DESC_NUM - 1),
               &mac_regs->rx_dsc_size);

        writel(dm_pci_phys_to_mem(priv->dev, (ulong)(rx_desc + 1)),
               &mac_regs->rx_dsc_sw_p);
}

static void pch_gbe_tx_descs_init(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;
        struct pch_gbe_tx_desc *tx_desc = &priv->tx_desc[0];

        memset(tx_desc, 0, sizeof(struct pch_gbe_tx_desc) * PCH_GBE_DESC_NUM);

        writel(dm_pci_phys_to_mem(priv->dev, (ulong)tx_desc),
               &mac_regs->tx_dsc_base);
        writel(sizeof(struct pch_gbe_tx_desc) * (PCH_GBE_DESC_NUM - 1),
               &mac_regs->tx_dsc_size);
        writel(dm_pci_phys_to_mem(priv->dev, (ulong)(tx_desc + 1)),
               &mac_regs->tx_dsc_sw_p);
}

static void pch_gbe_adjust_link(struct pch_gbe_regs *mac_regs,
                                struct phy_device *phydev)
{
        if (!phydev->link) {
                printf("%s: No link.\n", phydev->dev->name);
                return;
        }

        clrbits_le32(&mac_regs->rgmii_ctrl,
                     PCH_GBE_RGMII_RATE_2_5M | PCH_GBE_CRS_SEL);
        clrbits_le32(&mac_regs->mode,
                     PCH_GBE_MODE_GMII_ETHER | PCH_GBE_MODE_FULL_DUPLEX);

        switch (phydev->speed) {
        case 1000:
                setbits_le32(&mac_regs->rgmii_ctrl, PCH_GBE_RGMII_RATE_125M);
                setbits_le32(&mac_regs->mode, PCH_GBE_MODE_GMII_ETHER);
                break;
        case 100:
                setbits_le32(&mac_regs->rgmii_ctrl, PCH_GBE_RGMII_RATE_25M);
                setbits_le32(&mac_regs->mode, PCH_GBE_MODE_MII_ETHER);
                break;
        case 10:
                setbits_le32(&mac_regs->rgmii_ctrl, PCH_GBE_RGMII_RATE_2_5M);
                setbits_le32(&mac_regs->mode, PCH_GBE_MODE_MII_ETHER);
                break;
        }

        if (phydev->duplex) {
                setbits_le32(&mac_regs->rgmii_ctrl, PCH_GBE_CRS_SEL);
                setbits_le32(&mac_regs->mode, PCH_GBE_MODE_FULL_DUPLEX);
        }

        printf("Speed: %d, %s duplex\n", phydev->speed,
               (phydev->duplex) ? "full" : "half");

        return;
}

static int pch_gbe_start(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;

        if (pch_gbe_reset(dev))
                return -1;

        pch_gbe_rx_descs_init(dev);
        pch_gbe_tx_descs_init(dev);

        /* Enable frame bursting */
        writel(PCH_GBE_MODE_FR_BST, &mac_regs->mode);
        /* Disable TCP/IP accelerator */
        writel(PCH_GBE_RX_TCPIPACC_OFF, &mac_regs->tcpip_acc);
        /* Disable RX flow control */
        writel(0, &mac_regs->rx_fctrl);
        /* Configure RX/TX mode */
        writel(PCH_GBE_RH_ALM_EMP_16 | PCH_GBE_RH_ALM_FULL_16 |
               PCH_GBE_RH_RD_TRG_32, &mac_regs->rx_mode);
        writel(PCH_GBE_TM_TH_TX_STRT_32 | PCH_GBE_TM_TH_ALM_EMP_16 |
               PCH_GBE_TM_TH_ALM_FULL_32 | PCH_GBE_TM_ST_AND_FD |
               PCH_GBE_TM_SHORT_PKT, &mac_regs->tx_mode);

        /* Start up the PHY */
        if (phy_startup(priv->phydev)) {
                printf("Could not initialize PHY %s\n",
                       priv->phydev->dev->name);
                return -1;
        }

        pch_gbe_adjust_link(mac_regs, priv->phydev);

        if (!priv->phydev->link)
                return -1;

        /* Enable TX & RX */
        writel(PCH_GBE_RX_DMA_EN | PCH_GBE_TX_DMA_EN, &mac_regs->dma_ctrl);
        writel(PCH_GBE_MRE_MAC_RX_EN, &mac_regs->mac_rx_en);

        return 0;
}

static void pch_gbe_stop(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);

        pch_gbe_reset(dev);

        phy_shutdown(priv->phydev);
}

static int pch_gbe_send(struct udevice *dev, void *packet, int length)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;
        struct pch_gbe_tx_desc *tx_head, *tx_desc;
        u16 frame_ctrl = 0;
        u32 int_st;
        ulong start;

        tx_head = &priv->tx_desc[0];
        tx_desc = &priv->tx_desc[priv->tx_idx];

        if (length < 64)
                frame_ctrl |= PCH_GBE_TXD_CTRL_APAD;

        tx_desc->buffer_addr = dm_pci_phys_to_mem(priv->dev, (ulong)packet);
        tx_desc->length = length;
        tx_desc->tx_words_eob = length + 3;
        tx_desc->tx_frame_ctrl = frame_ctrl;
        tx_desc->dma_status = 0;
        tx_desc->gbec_status = 0;

        /* Test the wrap-around condition */
        if (++priv->tx_idx >= PCH_GBE_DESC_NUM)
                priv->tx_idx = 0;

        writel(dm_pci_phys_to_mem(priv->dev, (ulong)(tx_head + priv->tx_idx)),
               &mac_regs->tx_dsc_sw_p);

        start = get_timer(0);
        while (get_timer(start) < PCH_GBE_TIMEOUT) {
                int_st = readl(&mac_regs->int_st);
                if (int_st & PCH_GBE_INT_TX_CMPLT)
                        return 0;

                udelay(10);
        }

        debug("pch_gbe: sent failed\n");
        return -ETIME;
}

static int pch_gbe_recv(struct udevice *dev, int flags, uchar **packetp)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;
        struct pch_gbe_rx_desc *rx_desc;
        ulong hw_desc, buffer_addr, length;

        rx_desc = &priv->rx_desc[priv->rx_idx];

        readl(&mac_regs->int_st);
        hw_desc = readl(&mac_regs->rx_dsc_hw_p_hld);

        /* Just return if not receiving any packet */
        if ((ulong)rx_desc == hw_desc)
                return -EAGAIN;

        buffer_addr = dm_pci_mem_to_phys(priv->dev, rx_desc->buffer_addr);
        *packetp = (uchar *)buffer_addr;
        length = rx_desc->rx_words_eob - 3 - ETH_FCS_LEN;

        return length;
}

static int pch_gbe_free_pkt(struct udevice *dev, uchar *packet, int length)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct pch_gbe_regs *mac_regs = priv->mac_regs;
        struct pch_gbe_rx_desc *rx_head = &priv->rx_desc[0];
        int rx_swp;

        /* Test the wrap-around condition */
        if (++priv->rx_idx >= PCH_GBE_DESC_NUM)
                priv->rx_idx = 0;
        rx_swp = priv->rx_idx;
        if (++rx_swp >= PCH_GBE_DESC_NUM)
                rx_swp = 0;

        writel(dm_pci_phys_to_mem(priv->dev, (ulong)(rx_head + rx_swp)),
               &mac_regs->rx_dsc_sw_p);

        return 0;
}

static int pch_gbe_mdio_ready(struct pch_gbe_regs *mac_regs)
{
        ulong start = get_timer(0);

        while (get_timer(start) < PCH_GBE_TIMEOUT) {
                if (readl(&mac_regs->miim) & PCH_GBE_MIIM_OPER_READY)
                        return 0;

                udelay(10);
        }

        return -ETIME;
}

static int pch_gbe_mdio_read(struct mii_dev *bus, int addr, int devad, int reg)
{
        struct pch_gbe_regs *mac_regs = bus->priv;
        u32 miim;

        if (pch_gbe_mdio_ready(mac_regs))
                return -ETIME;

        miim = (addr << PCH_GBE_MIIM_PHY_ADDR_SHIFT) |
               (reg << PCH_GBE_MIIM_REG_ADDR_SHIFT) |
               PCH_GBE_MIIM_OPER_READ;
        writel(miim, &mac_regs->miim);

        if (pch_gbe_mdio_ready(mac_regs))
                return -ETIME;

        return readl(&mac_regs->miim) & 0xffff;
}

static int pch_gbe_mdio_write(struct mii_dev *bus, int addr, int devad,
                              int reg, u16 val)
{
        struct pch_gbe_regs *mac_regs = bus->priv;
        u32 miim;

        if (pch_gbe_mdio_ready(mac_regs))
                return -ETIME;

        miim = (addr << PCH_GBE_MIIM_PHY_ADDR_SHIFT) |
               (reg << PCH_GBE_MIIM_REG_ADDR_SHIFT) |
               PCH_GBE_MIIM_OPER_WRITE | val;
        writel(miim, &mac_regs->miim);

        if (pch_gbe_mdio_ready(mac_regs))
                return -ETIME;
        else
                return 0;
}

static int pch_gbe_mdio_init(const char *name, struct pch_gbe_regs *mac_regs)
{
        struct mii_dev *bus;

        bus = mdio_alloc();
        if (!bus) {
                debug("pch_gbe: failed to allocate MDIO bus\n");
                return -ENOMEM;
        }

        bus->read = pch_gbe_mdio_read;
        bus->write = pch_gbe_mdio_write;
        strcpy(bus->name, name);

        bus->priv = (void *)mac_regs;

        return mdio_register(bus);
}

static int pch_gbe_phy_init(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);
        struct eth_pdata *plat = dev_get_platdata(dev);
        struct phy_device *phydev;
        int mask = 0xffffffff;

        phydev = phy_find_by_mask(priv->bus, mask, plat->phy_interface);
        if (!phydev) {
                printf("pch_gbe: cannot find the phy\n");
                return -1;
        }

        phy_connect_dev(phydev, dev);

        phydev->supported &= PHY_GBIT_FEATURES;
        phydev->advertising = phydev->supported;

        priv->phydev = phydev;
        phy_config(phydev);

        return 0;
}

int pch_gbe_probe(struct udevice *dev)
{
        struct pch_gbe_priv *priv;
        struct eth_pdata *plat = dev_get_platdata(dev);
        void *iobase;

        /*
         * The priv structure contains the descriptors and frame buffers which
         * need a strict buswidth alignment (64 bytes). This is guaranteed by
         * DM_FLAG_ALLOC_PRIV_DMA flag in the U_BOOT_DRIVER.
         */
        priv = dev_get_priv(dev);

        priv->dev = dev;

        iobase = dm_pci_map_bar(dev, PCI_BASE_ADDRESS_1, PCI_REGION_MEM);

        plat->iobase = (ulong)iobase;
        priv->mac_regs = (struct pch_gbe_regs *)iobase;

        /* Read MAC address from SROM and initialize dev->enetaddr with it */
        pch_gbe_mac_read(priv->mac_regs, plat->enetaddr);

        plat->phy_interface = PHY_INTERFACE_MODE_RGMII;
        pch_gbe_mdio_init(dev->name, priv->mac_regs);
        priv->bus = miiphy_get_dev_by_name(dev->name);

        return pch_gbe_phy_init(dev);
}

int pch_gbe_remove(struct udevice *dev)
{
        struct pch_gbe_priv *priv = dev_get_priv(dev);

        free(priv->phydev);
        mdio_unregister(priv->bus);
        mdio_free(priv->bus);

        return 0;
}

static const struct eth_ops pch_gbe_ops = {
        .start = pch_gbe_start,
        .send = pch_gbe_send,
        .recv = pch_gbe_recv,
        .free_pkt = pch_gbe_free_pkt,
        .stop = pch_gbe_stop,
};

static const struct udevice_id pch_gbe_ids[] = {
        { .compatible = "intel,pch-gbe" },
        { }
};

U_BOOT_DRIVER(eth_pch_gbe) = {
        .name = "pch_gbe",
        .id = UCLASS_ETH,
        .of_match = pch_gbe_ids,
        .probe = pch_gbe_probe,
        .remove = pch_gbe_remove,
        .ops = &pch_gbe_ops,
        .priv_auto_alloc_size = sizeof(struct pch_gbe_priv),
        .platdata_auto_alloc_size = sizeof(struct eth_pdata),
        .flags = DM_FLAG_ALLOC_PRIV_DMA,
};

U_BOOT_PCI_DEVICE(eth_pch_gbe, supported);