// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2016
 * Author: Amit Singh Tomar, amittomer25@gmail.com
 *
 * Ethernet driver for H3/A64/A83T based SoC's
 *
 * It is derived from the work done by
 * LABBE Corentin & Chen-Yu Tsai for Linux, THANKS!
 *
*/

#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/gpio.h>
#include <common.h>
#include <dm.h>
#include <fdt_support.h>
#include <linux/err.h>
#include <malloc.h>
#include <miiphy.h>
#include <net.h>
#include <dt-bindings/pinctrl/sun4i-a10.h>
#ifdef CONFIG_DM_GPIO
#include <asm-generic/gpio.h>
#endif

#define MDIO_CMD_MII_BUSY               BIT(0)
#define MDIO_CMD_MII_WRITE              BIT(1)

#define MDIO_CMD_MII_PHY_REG_ADDR_MASK  0x000001f0
#define MDIO_CMD_MII_PHY_REG_ADDR_SHIFT 4
#define MDIO_CMD_MII_PHY_ADDR_MASK      0x0001f000
#define MDIO_CMD_MII_PHY_ADDR_SHIFT     12

#define CONFIG_TX_DESCR_NUM     32
#define CONFIG_RX_DESCR_NUM     32
#define CONFIG_ETH_BUFSIZE      2048 /* Note must be dma aligned */

/*
 * The datasheet says that each descriptor can transfers up to 4096 bytes
 * But later, the register documentation reduces that value to 2048,
 * using 2048 cause strange behaviours and even BSP driver use 2047
 */
#define CONFIG_ETH_RXSIZE       2044 /* Note must fit in ETH_BUFSIZE */

#define TX_TOTAL_BUFSIZE        (CONFIG_ETH_BUFSIZE * CONFIG_TX_DESCR_NUM)
#define RX_TOTAL_BUFSIZE        (CONFIG_ETH_BUFSIZE * CONFIG_RX_DESCR_NUM)

#define H3_EPHY_DEFAULT_VALUE   0x58000
#define H3_EPHY_DEFAULT_MASK    GENMASK(31, 15)
#define H3_EPHY_ADDR_SHIFT      20
#define REG_PHY_ADDR_MASK       GENMASK(4, 0)
#define H3_EPHY_LED_POL         BIT(17) /* 1: active low, 0: active high */
#define H3_EPHY_SHUTDOWN        BIT(16) /* 1: shutdown, 0: power up */
#define H3_EPHY_SELECT          BIT(15) /* 1: internal PHY, 0: external PHY */

#define SC_RMII_EN              BIT(13)
#define SC_EPIT                 BIT(2) /* 1: RGMII, 0: MII */
#define SC_ETCS_MASK            GENMASK(1, 0)
#define SC_ETCS_EXT_GMII        0x1
#define SC_ETCS_INT_GMII        0x2
#define SC_ETXDC_MASK           GENMASK(12, 10)
#define SC_ETXDC_OFFSET         10
#define SC_ERXDC_MASK           GENMASK(9, 5)
#define SC_ERXDC_OFFSET         5

#define CONFIG_MDIO_TIMEOUT     (3 * CONFIG_SYS_HZ)

#define AHB_GATE_OFFSET_EPHY    0

/* IO mux settings */
#define SUN8I_IOMUX_H3          2
#define SUN8I_IOMUX_R40 5
#define SUN8I_IOMUX             4

/* H3/A64 EMAC Register's offset */
#define EMAC_CTL0               0x00
#define EMAC_CTL1               0x04
#define EMAC_INT_STA            0x08
#define EMAC_INT_EN             0x0c
#define EMAC_TX_CTL0            0x10
#define EMAC_TX_CTL1            0x14
#define EMAC_TX_FLOW_CTL        0x1c
#define EMAC_TX_DMA_DESC        0x20
#define EMAC_RX_CTL0            0x24
#define EMAC_RX_CTL1            0x28
#define EMAC_RX_DMA_DESC        0x34
#define EMAC_MII_CMD            0x48
#define EMAC_MII_DATA           0x4c
#define EMAC_ADDR0_HIGH         0x50
#define EMAC_ADDR0_LOW          0x54
#define EMAC_TX_DMA_STA         0xb0
#define EMAC_TX_CUR_DESC        0xb4
#define EMAC_TX_CUR_BUF         0xb8
#define EMAC_RX_DMA_STA         0xc0
#define EMAC_RX_CUR_DESC        0xc4

DECLARE_GLOBAL_DATA_PTR;

enum emac_variant {
        A83T_EMAC = 1,
        H3_EMAC,
        A64_EMAC,
        R40_GMAC,
};

struct emac_dma_desc {
        u32 status;
        u32 st;
        u32 buf_addr;
        u32 next;
} __aligned(ARCH_DMA_MINALIGN);

struct emac_eth_dev {
        struct emac_dma_desc rx_chain[CONFIG_TX_DESCR_NUM];
        struct emac_dma_desc tx_chain[CONFIG_RX_DESCR_NUM];
        char rxbuffer[RX_TOTAL_BUFSIZE] __aligned(ARCH_DMA_MINALIGN);
        char txbuffer[TX_TOTAL_BUFSIZE] __aligned(ARCH_DMA_MINALIGN);

        u32 interface;
        u32 phyaddr;
        u32 link;
        u32 speed;
        u32 duplex;
        u32 phy_configured;
        u32 tx_currdescnum;
        u32 rx_currdescnum;
        u32 addr;
        u32 tx_slot;
        bool use_internal_phy;

        enum emac_variant variant;
        void *mac_reg;
        phys_addr_t sysctl_reg;
        struct phy_device *phydev;
        struct mii_dev *bus;
#ifdef CONFIG_DM_GPIO
        struct gpio_desc reset_gpio;
#endif
};


struct sun8i_eth_pdata {
        struct eth_pdata eth_pdata;
        u32 reset_delays[3];
        int tx_delay_ps;
        int rx_delay_ps;
};


static int sun8i_mdio_read(struct mii_dev *bus, int addr, int devad, int reg)
{
        struct udevice *dev = bus->priv;
        struct emac_eth_dev *priv = dev_get_priv(dev);
        ulong start;
        u32 miiaddr = 0;
        int timeout = CONFIG_MDIO_TIMEOUT;

        miiaddr &= ~MDIO_CMD_MII_WRITE;
        miiaddr &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK;
        miiaddr |= (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_REG_ADDR_MASK;

        miiaddr &= ~MDIO_CMD_MII_PHY_ADDR_MASK;

        miiaddr |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_ADDR_MASK;

        miiaddr |= MDIO_CMD_MII_BUSY;

        writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);

        start = get_timer(0);
        while (get_timer(start) < timeout) {
                if (!(readl(priv->mac_reg + EMAC_MII_CMD) & MDIO_CMD_MII_BUSY))
                        return readl(priv->mac_reg + EMAC_MII_DATA);
                udelay(10);
        };

        return -1;
}

static int sun8i_mdio_write(struct mii_dev *bus, int addr, int devad, int reg,
                            u16 val)
{
        struct udevice *dev = bus->priv;
        struct emac_eth_dev *priv = dev_get_priv(dev);
        ulong start;
        u32 miiaddr = 0;
        int ret = -1, timeout = CONFIG_MDIO_TIMEOUT;

        miiaddr &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK;
        miiaddr |= (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_REG_ADDR_MASK;

        miiaddr &= ~MDIO_CMD_MII_PHY_ADDR_MASK;
        miiaddr |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_ADDR_MASK;

        miiaddr |= MDIO_CMD_MII_WRITE;
        miiaddr |= MDIO_CMD_MII_BUSY;

        writel(val, priv->mac_reg + EMAC_MII_DATA);
        writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);

        start = get_timer(0);
        while (get_timer(start) < timeout) {
                if (!(readl(priv->mac_reg + EMAC_MII_CMD) &
                                        MDIO_CMD_MII_BUSY)) {
                        ret = 0;
                        break;
                }
                udelay(10);
        };

        return ret;
}

static int _sun8i_write_hwaddr(struct emac_eth_dev *priv, u8 *mac_id)
{
        u32 macid_lo, macid_hi;

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

        writel(macid_hi, priv->mac_reg + EMAC_ADDR0_HIGH);
        writel(macid_lo, priv->mac_reg + EMAC_ADDR0_LOW);

        return 0;
}

static void sun8i_adjust_link(struct emac_eth_dev *priv,
                              struct phy_device *phydev)
{
        u32 v;

        v = readl(priv->mac_reg + EMAC_CTL0);

        if (phydev->duplex)
                v |= BIT(0);
        else
                v &= ~BIT(0);

        v &= ~0x0C;

        switch (phydev->speed) {
        case 1000:
                break;
        case 100:
                v |= BIT(2);
                v |= BIT(3);
                break;
        case 10:
                v |= BIT(3);
                break;
        }
        writel(v, priv->mac_reg + EMAC_CTL0);
}

static int sun8i_emac_set_syscon_ephy(struct emac_eth_dev *priv, u32 *reg)
{
        if (priv->use_internal_phy) {
                /* H3 based SoC's that has an Internal 100MBit PHY
                 * needs to be configured and powered up before use
                */
                *reg &= ~H3_EPHY_DEFAULT_MASK;
                *reg |=  H3_EPHY_DEFAULT_VALUE;
                *reg |= priv->phyaddr << H3_EPHY_ADDR_SHIFT;
                *reg &= ~H3_EPHY_SHUTDOWN;
                *reg |= H3_EPHY_SELECT;
        } else
                /* This is to select External Gigabit PHY on
                 * the boards with H3 SoC.
                */
                *reg &= ~H3_EPHY_SELECT;

        return 0;
}

static int sun8i_emac_set_syscon(struct sun8i_eth_pdata *pdata,
                                 struct emac_eth_dev *priv)
{
        int ret;
        u32 reg;

        reg = readl(priv->sysctl_reg + 0x30);

        if (priv->variant == R40_GMAC)
                return 0;

        if (priv->variant == H3_EMAC) {
                ret = sun8i_emac_set_syscon_ephy(priv, &reg);
                if (ret)
                        return ret;
        }

        reg &= ~(SC_ETCS_MASK | SC_EPIT);
        if (priv->variant == H3_EMAC || priv->variant == A64_EMAC)
                reg &= ~SC_RMII_EN;

        switch (priv->interface) {
        case PHY_INTERFACE_MODE_MII:
                /* default */
                break;
        case PHY_INTERFACE_MODE_RGMII:
                reg |= SC_EPIT | SC_ETCS_INT_GMII;
                break;
        case PHY_INTERFACE_MODE_RMII:
                if (priv->variant == H3_EMAC ||
                    priv->variant == A64_EMAC) {
                        reg |= SC_RMII_EN | SC_ETCS_EXT_GMII;
                break;
                }
                /* RMII not supported on A83T */
        default:
                debug("%s: Invalid PHY interface\n", __func__);
                return -EINVAL;
        }

        if (pdata->tx_delay_ps)
                reg |= ((pdata->tx_delay_ps / 100) << SC_ETXDC_OFFSET)
                         & SC_ETXDC_MASK;

        if (pdata->rx_delay_ps)
                reg |= ((pdata->rx_delay_ps / 100) << SC_ERXDC_OFFSET)
                         & SC_ERXDC_MASK;

        writel(reg, priv->sysctl_reg + 0x30);

        return 0;
}

static int sun8i_phy_init(struct emac_eth_dev *priv, void *dev)
{
        struct phy_device *phydev;

        phydev = phy_connect(priv->bus, priv->phyaddr, dev, priv->interface);
        if (!phydev)
                return -ENODEV;

        phy_connect_dev(phydev, dev);

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

        return 0;
}

static void rx_descs_init(struct emac_eth_dev *priv)
{
        struct emac_dma_desc *desc_table_p = &priv->rx_chain[0];
        char *rxbuffs = &priv->rxbuffer[0];
        struct emac_dma_desc *desc_p;
        u32 idx;

        /* flush Rx buffers */
        flush_dcache_range((uintptr_t)rxbuffs, (ulong)rxbuffs +
                        RX_TOTAL_BUFSIZE);

        for (idx = 0; idx < CONFIG_RX_DESCR_NUM; idx++) {
                desc_p = &desc_table_p[idx];
                desc_p->buf_addr = (uintptr_t)&rxbuffs[idx * CONFIG_ETH_BUFSIZE]
                        ;
                desc_p->next = (uintptr_t)&desc_table_p[idx + 1];
                desc_p->st |= CONFIG_ETH_RXSIZE;
                desc_p->status = BIT(31);
        }

        /* Correcting the last pointer of the chain */
        desc_p->next = (uintptr_t)&desc_table_p[0];

        flush_dcache_range((uintptr_t)priv->rx_chain,
                           (uintptr_t)priv->rx_chain +
                        sizeof(priv->rx_chain));

        writel((uintptr_t)&desc_table_p[0], (priv->mac_reg + EMAC_RX_DMA_DESC));
        priv->rx_currdescnum = 0;
}

static void tx_descs_init(struct emac_eth_dev *priv)
{
        struct emac_dma_desc *desc_table_p = &priv->tx_chain[0];
        char *txbuffs = &priv->txbuffer[0];
        struct emac_dma_desc *desc_p;
        u32 idx;

        for (idx = 0; idx < CONFIG_TX_DESCR_NUM; idx++) {
                desc_p = &desc_table_p[idx];
                desc_p->buf_addr = (uintptr_t)&txbuffs[idx * CONFIG_ETH_BUFSIZE]
                        ;
                desc_p->next = (uintptr_t)&desc_table_p[idx + 1];
                desc_p->status = (1 << 31);
                desc_p->st = 0;
        }

        /* Correcting the last pointer of the chain */
        desc_p->next =  (uintptr_t)&desc_table_p[0];

        /* Flush all Tx buffer descriptors */
        flush_dcache_range((uintptr_t)priv->tx_chain,
                           (uintptr_t)priv->tx_chain +
                        sizeof(priv->tx_chain));

        writel((uintptr_t)&desc_table_p[0], priv->mac_reg + EMAC_TX_DMA_DESC);
        priv->tx_currdescnum = 0;
}

static int _sun8i_emac_eth_init(struct emac_eth_dev *priv, u8 *enetaddr)
{
        u32 reg, v;
        int timeout = 100;

        reg = readl((priv->mac_reg + EMAC_CTL1));

        if (!(reg & 0x1)) {
                /* Soft reset MAC */
                setbits_le32((priv->mac_reg + EMAC_CTL1), 0x1);
                do {
                        reg = readl(priv->mac_reg + EMAC_CTL1);
                } while ((reg & 0x01) != 0 &&  (--timeout));
                if (!timeout) {
                        printf("%s: Timeout\n", __func__);
                        return -1;
                }
        }

        /* Rewrite mac address after reset */
        _sun8i_write_hwaddr(priv, enetaddr);

        v = readl(priv->mac_reg + EMAC_TX_CTL1);
        /* TX_MD Transmission starts after a full frame located in TX DMA FIFO*/
        v |= BIT(1);
        writel(v, priv->mac_reg + EMAC_TX_CTL1);

        v = readl(priv->mac_reg + EMAC_RX_CTL1);
        /* RX_MD RX DMA reads data from RX DMA FIFO to host memory after a
         * complete frame has been written to RX DMA FIFO
         */
        v |= BIT(1);
        writel(v, priv->mac_reg + EMAC_RX_CTL1);

        /* DMA */
        writel(8 << 24, priv->mac_reg + EMAC_CTL1);

        /* Initialize rx/tx descriptors */
        rx_descs_init(priv);
        tx_descs_init(priv);

        /* PHY Start Up */
        phy_startup(priv->phydev);

        sun8i_adjust_link(priv, priv->phydev);

        /* Start RX DMA */
        v = readl(priv->mac_reg + EMAC_RX_CTL1);
        v |= BIT(30);
        writel(v, priv->mac_reg + EMAC_RX_CTL1);
        /* Start TX DMA */
        v = readl(priv->mac_reg + EMAC_TX_CTL1);
        v |= BIT(30);
        writel(v, priv->mac_reg + EMAC_TX_CTL1);

        /* Enable RX/TX */
        setbits_le32(priv->mac_reg + EMAC_RX_CTL0, BIT(31));
        setbits_le32(priv->mac_reg + EMAC_TX_CTL0, BIT(31));

        return 0;
}

static int parse_phy_pins(struct udevice *dev)
{
        struct emac_eth_dev *priv = dev_get_priv(dev);
        int offset;
        const char *pin_name;
        int drive, pull = SUN4I_PINCTRL_NO_PULL, i;

        offset = fdtdec_lookup_phandle(gd->fdt_blob, dev_of_offset(dev),
                                       "pinctrl-0");
        if (offset < 0) {
                printf("WARNING: emac: cannot find pinctrl-0 node\n");
                return offset;
        }

        drive = fdt_getprop_u32_default_node(gd->fdt_blob, offset, 0,
                                             "drive-strength", ~0);
        if (drive != ~0) {
                if (drive <= 10)
                        drive = SUN4I_PINCTRL_10_MA;
                else if (drive <= 20)
                        drive = SUN4I_PINCTRL_20_MA;
                else if (drive <= 30)
                        drive = SUN4I_PINCTRL_30_MA;
                else
                        drive = SUN4I_PINCTRL_40_MA;
        }

        if (fdt_get_property(gd->fdt_blob, offset, "bias-pull-up", NULL))
                pull = SUN4I_PINCTRL_PULL_UP;
        else if (fdt_get_property(gd->fdt_blob, offset, "bias-pull-down", NULL))
                pull = SUN4I_PINCTRL_PULL_DOWN;

        for (i = 0; ; i++) {
                int pin;

                pin_name = fdt_stringlist_get(gd->fdt_blob, offset,
                                              "pins", i, NULL);
                if (!pin_name)
                        break;

                pin = sunxi_name_to_gpio(pin_name);
                if (pin < 0)
                        continue;

                if (priv->variant == H3_EMAC)
                        sunxi_gpio_set_cfgpin(pin, SUN8I_IOMUX_H3);
                else if (priv->variant == R40_GMAC)
                        sunxi_gpio_set_cfgpin(pin, SUN8I_IOMUX_R40);
                else
                        sunxi_gpio_set_cfgpin(pin, SUN8I_IOMUX);

                if (drive != ~0)
                        sunxi_gpio_set_drv(pin, drive);
                if (pull != ~0)
                        sunxi_gpio_set_pull(pin, pull);
        }

        if (!i) {
                printf("WARNING: emac: cannot find pins property\n");
                return -2;
        }

        return 0;
}

static int _sun8i_eth_recv(struct emac_eth_dev *priv, uchar **packetp)
{
        u32 status, desc_num = priv->rx_currdescnum;
        struct emac_dma_desc *desc_p = &priv->rx_chain[desc_num];
        int length = -EAGAIN;
        int good_packet = 1;
        uintptr_t desc_start = (uintptr_t)desc_p;
        uintptr_t desc_end = desc_start +
                roundup(sizeof(*desc_p), ARCH_DMA_MINALIGN);

        ulong data_start = (uintptr_t)desc_p->buf_addr;
        ulong data_end;

        /* Invalidate entire buffer descriptor */
        invalidate_dcache_range(desc_start, desc_end);

        status = desc_p->status;

        /* Check for DMA own bit */
        if (!(status & BIT(31))) {
                length = (desc_p->status >> 16) & 0x3FFF;

                if (length < 0x40) {
                        good_packet = 0;
                        debug("RX: Bad Packet (runt)\n");
                }

                data_end = data_start + length;
                /* Invalidate received data */
                invalidate_dcache_range(rounddown(data_start,
                                                  ARCH_DMA_MINALIGN),
                                        roundup(data_end,
                                                ARCH_DMA_MINALIGN));
                if (good_packet) {
                        if (length > CONFIG_ETH_RXSIZE) {
                                printf("Received packet is too big (len=%d)\n",
                                       length);
                                return -EMSGSIZE;
                        }
                        *packetp = (uchar *)(ulong)desc_p->buf_addr;
                        return length;
                }
        }

        return length;
}

static int _sun8i_emac_eth_send(struct emac_eth_dev *priv, void *packet,
                                int len)
{
        u32 v, desc_num = priv->tx_currdescnum;
        struct emac_dma_desc *desc_p = &priv->tx_chain[desc_num];
        uintptr_t desc_start = (uintptr_t)desc_p;
        uintptr_t desc_end = desc_start +
                roundup(sizeof(*desc_p), ARCH_DMA_MINALIGN);

        uintptr_t data_start = (uintptr_t)desc_p->buf_addr;
        uintptr_t data_end = data_start +
                roundup(len, ARCH_DMA_MINALIGN);

        /* Invalidate entire buffer descriptor */
        invalidate_dcache_range(desc_start, desc_end);

        desc_p->st = len;
        /* Mandatory undocumented bit */
        desc_p->st |= BIT(24);

        memcpy((void *)data_start, packet, len);

        /* Flush data to be sent */
        flush_dcache_range(data_start, data_end);

        /* frame end */
        desc_p->st |= BIT(30);
        desc_p->st |= BIT(31);

        /*frame begin */
        desc_p->st |= BIT(29);
        desc_p->status = BIT(31);

        /*Descriptors st and status field has changed, so FLUSH it */
        flush_dcache_range(desc_start, desc_end);

        /* Move to next Descriptor and wrap around */
        if (++desc_num >= CONFIG_TX_DESCR_NUM)
                desc_num = 0;
        priv->tx_currdescnum = desc_num;

        /* Start the DMA */
        v = readl(priv->mac_reg + EMAC_TX_CTL1);
        v |= BIT(31);/* mandatory */
        v |= BIT(30);/* mandatory */
        writel(v, priv->mac_reg + EMAC_TX_CTL1);

        return 0;
}

static int sun8i_eth_write_hwaddr(struct udevice *dev)
{
        struct eth_pdata *pdata = dev_get_platdata(dev);
        struct emac_eth_dev *priv = dev_get_priv(dev);

        return _sun8i_write_hwaddr(priv, pdata->enetaddr);
}

static void sun8i_emac_board_setup(struct emac_eth_dev *priv)
{
        struct sunxi_ccm_reg *ccm = (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;

        if (priv->variant == H3_EMAC) {
                /* Only H3/H5 have clock controls for internal EPHY */
                if (priv->use_internal_phy) {
                        /* Set clock gating for ephy */
                        setbits_le32(&ccm->bus_gate4,
                                     BIT(AHB_GATE_OFFSET_EPHY));

                        /* Deassert EPHY */
                        setbits_le32(&ccm->ahb_reset2_cfg,
                                     BIT(AHB_RESET_OFFSET_EPHY));
                }
        }

        if (priv->variant == R40_GMAC) {
                /* Set clock gating for emac */
                setbits_le32(&ccm->ahb_reset1_cfg, BIT(AHB_RESET_OFFSET_GMAC));

                /* De-assert EMAC */
                setbits_le32(&ccm->ahb_gate1, BIT(AHB_GATE_OFFSET_GMAC));

                /* Select RGMII for R40 */
                setbits_le32(&ccm->gmac_clk_cfg,
                             CCM_GMAC_CTRL_TX_CLK_SRC_INT_RGMII |
                             CCM_GMAC_CTRL_GPIT_RGMII);
                setbits_le32(&ccm->gmac_clk_cfg,
                             CCM_GMAC_CTRL_TX_CLK_DELAY(CONFIG_GMAC_TX_DELAY));
        } else {
                /* Set clock gating for emac */
                setbits_le32(&ccm->ahb_gate0, BIT(AHB_GATE_OFFSET_GMAC));

                /* De-assert EMAC */
                setbits_le32(&ccm->ahb_reset0_cfg, BIT(AHB_RESET_OFFSET_GMAC));
        }
}

#if defined(CONFIG_DM_GPIO)
static int sun8i_mdio_reset(struct mii_dev *bus)
{
        struct udevice *dev = bus->priv;
        struct emac_eth_dev *priv = dev_get_priv(dev);
        struct sun8i_eth_pdata *pdata = dev_get_platdata(dev);
        int ret;

        if (!dm_gpio_is_valid(&priv->reset_gpio))
                return 0;

        /* reset the phy */
        ret = dm_gpio_set_value(&priv->reset_gpio, 0);
        if (ret)
                return ret;

        udelay(pdata->reset_delays[0]);

        ret = dm_gpio_set_value(&priv->reset_gpio, 1);
        if (ret)
                return ret;

        udelay(pdata->reset_delays[1]);

        ret = dm_gpio_set_value(&priv->reset_gpio, 0);
        if (ret)
                return ret;

        udelay(pdata->reset_delays[2]);

        return 0;
}
#endif

static int sun8i_mdio_init(const char *name, struct udevice *priv)
{
        struct mii_dev *bus = mdio_alloc();

        if (!bus) {
                debug("Failed to allocate MDIO bus\n");
                return -ENOMEM;
        }

        bus->read = sun8i_mdio_read;
        bus->write = sun8i_mdio_write;
        snprintf(bus->name, sizeof(bus->name), name);
        bus->priv = (void *)priv;
#if defined(CONFIG_DM_GPIO)
        bus->reset = sun8i_mdio_reset;
#endif

        return  mdio_register(bus);
}

static int sun8i_emac_eth_start(struct udevice *dev)
{
        struct eth_pdata *pdata = dev_get_platdata(dev);

        return _sun8i_emac_eth_init(dev->priv, pdata->enetaddr);
}

static int sun8i_emac_eth_send(struct udevice *dev, void *packet, int length)
{
        struct emac_eth_dev *priv = dev_get_priv(dev);

        return _sun8i_emac_eth_send(priv, packet, length);
}

static int sun8i_emac_eth_recv(struct udevice *dev, int flags, uchar **packetp)
{
        struct emac_eth_dev *priv = dev_get_priv(dev);

        return _sun8i_eth_recv(priv, packetp);
}

static int _sun8i_free_pkt(struct emac_eth_dev *priv)
{
        u32 desc_num = priv->rx_currdescnum;
        struct emac_dma_desc *desc_p = &priv->rx_chain[desc_num];
        uintptr_t desc_start = (uintptr_t)desc_p;
        uintptr_t desc_end = desc_start +
                roundup(sizeof(u32), ARCH_DMA_MINALIGN);

        /* Make the current descriptor valid again */
        desc_p->status |= BIT(31);

        /* Flush Status field of descriptor */
        flush_dcache_range(desc_start, desc_end);

        /* Move to next desc and wrap-around condition. */
        if (++desc_num >= CONFIG_RX_DESCR_NUM)
                desc_num = 0;
        priv->rx_currdescnum = desc_num;

        return 0;
}

static int sun8i_eth_free_pkt(struct udevice *dev, uchar *packet,
                              int length)
{
        struct emac_eth_dev *priv = dev_get_priv(dev);

        return _sun8i_free_pkt(priv);
}

static void sun8i_emac_eth_stop(struct udevice *dev)
{
        struct emac_eth_dev *priv = dev_get_priv(dev);

        /* Stop Rx/Tx transmitter */
        clrbits_le32(priv->mac_reg + EMAC_RX_CTL0, BIT(31));
        clrbits_le32(priv->mac_reg + EMAC_TX_CTL0, BIT(31));

        /* Stop TX DMA */
        clrbits_le32(priv->mac_reg + EMAC_TX_CTL1, BIT(30));

        phy_shutdown(priv->phydev);
}

static int sun8i_emac_eth_probe(struct udevice *dev)
{
        struct sun8i_eth_pdata *sun8i_pdata = dev_get_platdata(dev);
        struct eth_pdata *pdata = &sun8i_pdata->eth_pdata;
        struct emac_eth_dev *priv = dev_get_priv(dev);

        priv->mac_reg = (void *)pdata->iobase;

        sun8i_emac_board_setup(priv);
        sun8i_emac_set_syscon(sun8i_pdata, priv);

        sun8i_mdio_init(dev->name, dev);
        priv->bus = miiphy_get_dev_by_name(dev->name);

        return sun8i_phy_init(priv, dev);
}

static const struct eth_ops sun8i_emac_eth_ops = {
        .start                  = sun8i_emac_eth_start,
        .write_hwaddr           = sun8i_eth_write_hwaddr,
        .send                   = sun8i_emac_eth_send,
        .recv                   = sun8i_emac_eth_recv,
        .free_pkt               = sun8i_eth_free_pkt,
        .stop                   = sun8i_emac_eth_stop,
};

static int sun8i_emac_eth_ofdata_to_platdata(struct udevice *dev)
{
        struct sun8i_eth_pdata *sun8i_pdata = dev_get_platdata(dev);
        struct eth_pdata *pdata = &sun8i_pdata->eth_pdata;
        struct emac_eth_dev *priv = dev_get_priv(dev);
        const char *phy_mode;
        const fdt32_t *reg;
        int node = dev_of_offset(dev);
        int offset = 0;
#ifdef CONFIG_DM_GPIO
        int reset_flags = GPIOD_IS_OUT;
        int ret = 0;
#endif

        pdata->iobase = devfdt_get_addr(dev);
        if (pdata->iobase == FDT_ADDR_T_NONE) {
                debug("%s: Cannot find MAC base address\n", __func__);
                return -EINVAL;
        }

        priv->variant = dev_get_driver_data(dev);

        if (!priv->variant) {
                printf("%s: Missing variant\n", __func__);
                return -EINVAL;
        }

        if (priv->variant != R40_GMAC) {
                offset = fdtdec_lookup_phandle(gd->fdt_blob, node, "syscon");
                if (offset < 0) {
                        debug("%s: cannot find syscon node\n", __func__);
                        return -EINVAL;
                }
                reg = fdt_getprop(gd->fdt_blob, offset, "reg", NULL);
                if (!reg) {
                        debug("%s: cannot find reg property in syscon node\n",
                              __func__);
                        return -EINVAL;
                }
                priv->sysctl_reg = fdt_translate_address((void *)gd->fdt_blob,
                                                         offset, reg);
                if (priv->sysctl_reg == FDT_ADDR_T_NONE) {
                        debug("%s: Cannot find syscon base address\n",
                              __func__);
                        return -EINVAL;
                }
        }

        pdata->phy_interface = -1;
        priv->phyaddr = -1;
        priv->use_internal_phy = false;

        offset = fdtdec_lookup_phandle(gd->fdt_blob, node, "phy-handle");
        if (offset < 0) {
                debug("%s: Cannot find PHY address\n", __func__);
                return -EINVAL;
        }
        priv->phyaddr = fdtdec_get_int(gd->fdt_blob, offset, "reg", -1);

        phy_mode = fdt_getprop(gd->fdt_blob, node, "phy-mode", NULL);

        if (phy_mode)
                pdata->phy_interface = phy_get_interface_by_name(phy_mode);
        printf("phy interface%d\n", pdata->phy_interface);

        if (pdata->phy_interface == -1) {
                debug("%s: Invalid PHY interface '%s'\n", __func__, phy_mode);
                return -EINVAL;
        }

        if (priv->variant == H3_EMAC) {
                int parent = fdt_parent_offset(gd->fdt_blob, offset);

                if (parent >= 0 &&
                    !fdt_node_check_compatible(gd->fdt_blob, parent,
                                "allwinner,sun8i-h3-mdio-internal"))
                        priv->use_internal_phy = true;
        }

        priv->interface = pdata->phy_interface;

        if (!priv->use_internal_phy)
                parse_phy_pins(dev);

        sun8i_pdata->tx_delay_ps = fdtdec_get_int(gd->fdt_blob, node,
                                                  "allwinner,tx-delay-ps", 0);
        if (sun8i_pdata->tx_delay_ps < 0 || sun8i_pdata->tx_delay_ps > 700)
                printf("%s: Invalid TX delay value %d\n", __func__,
                       sun8i_pdata->tx_delay_ps);

        sun8i_pdata->rx_delay_ps = fdtdec_get_int(gd->fdt_blob, node,
                                                  "allwinner,rx-delay-ps", 0);
        if (sun8i_pdata->rx_delay_ps < 0 || sun8i_pdata->rx_delay_ps > 3100)
                printf("%s: Invalid RX delay value %d\n", __func__,
                       sun8i_pdata->rx_delay_ps);

#ifdef CONFIG_DM_GPIO
        if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
                            "snps,reset-active-low"))
                reset_flags |= GPIOD_ACTIVE_LOW;

        ret = gpio_request_by_name(dev, "snps,reset-gpio", 0,
                                   &priv->reset_gpio, reset_flags);

        if (ret == 0) {
                ret = fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev),
                                           "snps,reset-delays-us",
                                           sun8i_pdata->reset_delays, 3);
        } else if (ret == -ENOENT) {
                ret = 0;
        }
#endif

        return 0;
}

static const struct udevice_id sun8i_emac_eth_ids[] = {
        {.compatible = "allwinner,sun8i-h3-emac", .data = (uintptr_t)H3_EMAC },
        {.compatible = "allwinner,sun50i-a64-emac",
                .data = (uintptr_t)A64_EMAC },
        {.compatible = "allwinner,sun8i-a83t-emac",
                .data = (uintptr_t)A83T_EMAC },
        {.compatible = "allwinner,sun8i-r40-gmac",
                .data = (uintptr_t)R40_GMAC },
        { }
};

U_BOOT_DRIVER(eth_sun8i_emac) = {
        .name   = "eth_sun8i_emac",
        .id     = UCLASS_ETH,
        .of_match = sun8i_emac_eth_ids,
        .ofdata_to_platdata = sun8i_emac_eth_ofdata_to_platdata,
        .probe  = sun8i_emac_eth_probe,
        .ops    = &sun8i_emac_eth_ops,
        .priv_auto_alloc_size = sizeof(struct emac_eth_dev),
        .platdata_auto_alloc_size = sizeof(struct sun8i_eth_pdata),
        .flags = DM_FLAG_ALLOC_PRIV_DMA,
};