// SPDX-License-Identifier: GPL-2.0
/* Copyright Sunplus Technology Co., Ltd.
 *       All rights reserved.
 */

#include <linux/platform_device.h>
#include <linux/nvmem-consumer.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/of_net.h>
#include <linux/reset.h>
#include <linux/clk.h>
#include <linux/of.h>

#include "spl2sw_register.h"
#include "spl2sw_define.h"
#include "spl2sw_desc.h"
#include "spl2sw_mdio.h"
#include "spl2sw_phy.h"
#include "spl2sw_int.h"
#include "spl2sw_mac.h"

/* net device operations */
static int spl2sw_ethernet_open(struct net_device *ndev)
{
        struct spl2sw_mac *mac = netdev_priv(ndev);
        struct spl2sw_common *comm = mac->comm;
        u32 mask;

        netdev_dbg(ndev, "Open port = %x\n", mac->lan_port);

        comm->enable |= mac->lan_port;

        spl2sw_mac_hw_start(comm);

        /* Enable TX and RX interrupts */
        mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
        mask &= ~(MAC_INT_TX | MAC_INT_RX);
        writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);

        phy_start(ndev->phydev);

        netif_start_queue(ndev);

        return 0;
}

static int spl2sw_ethernet_stop(struct net_device *ndev)
{
        struct spl2sw_mac *mac = netdev_priv(ndev);
        struct spl2sw_common *comm = mac->comm;

        netif_stop_queue(ndev);

        comm->enable &= ~mac->lan_port;

        phy_stop(ndev->phydev);

        spl2sw_mac_hw_stop(comm);

        return 0;
}

static netdev_tx_t spl2sw_ethernet_start_xmit(struct sk_buff *skb,
                                              struct net_device *ndev)
{
        struct spl2sw_mac *mac = netdev_priv(ndev);
        struct spl2sw_common *comm = mac->comm;
        struct spl2sw_skb_info *skbinfo;
        struct spl2sw_mac_desc *txdesc;
        unsigned long flags;
        u32 mapping;
        u32 tx_pos;
        u32 cmd1;
        u32 cmd2;

        if (unlikely(comm->tx_desc_full == 1)) {
                /* No TX descriptors left. Wait for tx interrupt. */
                netdev_dbg(ndev, "TX descriptor queue full when xmit!\n");
                return NETDEV_TX_BUSY;
        }

        /* If skb size is shorter than ETH_ZLEN (60), pad it with 0. */
        if (unlikely(skb->len < ETH_ZLEN)) {
                if (skb_padto(skb, ETH_ZLEN))
                        return NETDEV_TX_OK;

                skb_put(skb, ETH_ZLEN - skb->len);
        }

        mapping = dma_map_single(&comm->pdev->dev, skb->data,
                                 skb->len, DMA_TO_DEVICE);
        if (dma_mapping_error(&comm->pdev->dev, mapping)) {
                ndev->stats.tx_errors++;
                dev_kfree_skb(skb);
                return NETDEV_TX_OK;
        }

        spin_lock_irqsave(&comm->tx_lock, flags);

        tx_pos = comm->tx_pos;
        txdesc = &comm->tx_desc[tx_pos];
        skbinfo = &comm->tx_temp_skb_info[tx_pos];
        skbinfo->mapping = mapping;
        skbinfo->len = skb->len;
        skbinfo->skb = skb;

        /* Set up a TX descriptor */
        cmd1 = TXD_OWN | TXD_SOP | TXD_EOP | (mac->to_vlan << 12) |
               (skb->len & TXD_PKT_LEN);
        cmd2 = skb->len & TXD_BUF_LEN1;

        if (tx_pos == (TX_DESC_NUM - 1))
                cmd2 |= TXD_EOR;

        txdesc->addr1 = skbinfo->mapping;
        txdesc->cmd2 = cmd2;
        wmb();  /* Set TXD_OWN after other fields are effective. */
        txdesc->cmd1 = cmd1;

        /* Move tx_pos to next position */
        tx_pos = ((tx_pos + 1) == TX_DESC_NUM) ? 0 : tx_pos + 1;

        if (unlikely(tx_pos == comm->tx_done_pos)) {
                netif_stop_queue(ndev);
                comm->tx_desc_full = 1;
        }
        comm->tx_pos = tx_pos;
        wmb();          /* make sure settings are effective. */

        /* Trigger mac to transmit */
        writel(MAC_TRIG_L_SOC0, comm->l2sw_reg_base + L2SW_CPU_TX_TRIG);

        spin_unlock_irqrestore(&comm->tx_lock, flags);
        return NETDEV_TX_OK;
}

static void spl2sw_ethernet_set_rx_mode(struct net_device *ndev)
{
        struct spl2sw_mac *mac = netdev_priv(ndev);

        spl2sw_mac_rx_mode_set(mac);
}

static int spl2sw_ethernet_set_mac_address(struct net_device *ndev, void *addr)
{
        struct spl2sw_mac *mac = netdev_priv(ndev);
        int err;

        err = eth_mac_addr(ndev, addr);
        if (err)
                return err;

        /* Delete the old MAC address */
        netdev_dbg(ndev, "Old Ethernet (MAC) address = %pM\n", mac->mac_addr);
        if (is_valid_ether_addr(mac->mac_addr)) {
                err = spl2sw_mac_addr_del(mac);
                if (err)
                        return err;
        }

        /* Set the MAC address */
        ether_addr_copy(mac->mac_addr, ndev->dev_addr);
        return spl2sw_mac_addr_add(mac);
}

static void spl2sw_ethernet_tx_timeout(struct net_device *ndev, unsigned int txqueue)
{
        struct spl2sw_mac *mac = netdev_priv(ndev);
        struct spl2sw_common *comm = mac->comm;
        unsigned long flags;
        int i;

        netdev_err(ndev, "TX timed out!\n");
        ndev->stats.tx_errors++;

        spin_lock_irqsave(&comm->tx_lock, flags);

        for (i = 0; i < MAX_NETDEV_NUM; i++)
                if (comm->ndev[i])
                        netif_stop_queue(comm->ndev[i]);

        spl2sw_mac_soft_reset(comm);

        /* Accept TX packets again. */
        for (i = 0; i < MAX_NETDEV_NUM; i++)
                if (comm->ndev[i]) {
                        netif_trans_update(comm->ndev[i]);
                        netif_wake_queue(comm->ndev[i]);
                }

        spin_unlock_irqrestore(&comm->tx_lock, flags);
}

static const struct net_device_ops netdev_ops = {
        .ndo_open = spl2sw_ethernet_open,
        .ndo_stop = spl2sw_ethernet_stop,
        .ndo_start_xmit = spl2sw_ethernet_start_xmit,
        .ndo_set_rx_mode = spl2sw_ethernet_set_rx_mode,
        .ndo_set_mac_address = spl2sw_ethernet_set_mac_address,
        .ndo_eth_ioctl = phy_do_ioctl,
        .ndo_tx_timeout = spl2sw_ethernet_tx_timeout,
};

static void spl2sw_check_mac_vendor_id_and_convert(u8 *mac_addr)
{
        /* Byte order of MAC address of some samples are reversed.
         * Check vendor id and convert byte order if it is wrong.
         * OUI of Sunplus: fc:4b:bc
         */
        if (mac_addr[5] == 0xfc && mac_addr[4] == 0x4b && mac_addr[3] == 0xbc &&
            (mac_addr[0] != 0xfc || mac_addr[1] != 0x4b || mac_addr[2] != 0xbc)) {

                swap(mac_addr[0], mac_addr[5]);
                swap(mac_addr[1], mac_addr[4]);
                swap(mac_addr[2], mac_addr[3]);
        }
}

static int spl2sw_nvmem_get_mac_address(struct device *dev, struct device_node *np,
                                        void *addrbuf)
{
        struct nvmem_cell *cell;
        ssize_t len;
        u8 *mac;

        /* Get nvmem cell of mac-address from dts. */
        cell = of_nvmem_cell_get(np, "mac-address");
        if (IS_ERR(cell))
                return PTR_ERR(cell);

        /* Read mac address from nvmem cell. */
        mac = nvmem_cell_read(cell, &len);
        nvmem_cell_put(cell);
        if (IS_ERR(mac))
                return PTR_ERR(mac);

        if (len != ETH_ALEN) {
                kfree(mac);
                dev_info(dev, "Invalid length of mac address in nvmem!\n");
                return -EINVAL;
        }

        /* Byte order of some samples are reversed.
         * Convert byte order here.
         */
        spl2sw_check_mac_vendor_id_and_convert(mac);

        /* Check if mac address is valid */
        if (!is_valid_ether_addr(mac)) {
                dev_info(dev, "Invalid mac address in nvmem (%pM)!\n", mac);
                kfree(mac);
                return -EINVAL;
        }

        ether_addr_copy(addrbuf, mac);
        kfree(mac);
        return 0;
}

static u32 spl2sw_init_netdev(struct platform_device *pdev, u8 *mac_addr,
                              struct net_device **r_ndev)
{
        struct net_device *ndev;
        struct spl2sw_mac *mac;
        int ret;

        /* Allocate the devices, and also allocate spl2sw_mac,
         * we can get it by netdev_priv().
         */
        ndev = devm_alloc_etherdev(&pdev->dev, sizeof(*mac));
        if (!ndev) {
                *r_ndev = NULL;
                return -ENOMEM;
        }
        SET_NETDEV_DEV(ndev, &pdev->dev);
        ndev->netdev_ops = &netdev_ops;
        mac = netdev_priv(ndev);
        mac->ndev = ndev;
        ether_addr_copy(mac->mac_addr, mac_addr);

        eth_hw_addr_set(ndev, mac_addr);
        dev_info(&pdev->dev, "Ethernet (MAC) address = %pM\n", mac_addr);

        ret = register_netdev(ndev);
        if (ret) {
                dev_err(&pdev->dev, "Failed to register net device \"%s\"!\n",
                        ndev->name);
                *r_ndev = NULL;
                return ret;
        }
        netdev_dbg(ndev, "Registered net device \"%s\" successfully.\n", ndev->name);

        *r_ndev = ndev;
        return 0;
}

static struct device_node *spl2sw_get_eth_child_node(struct device_node *ether_np, int id)
{
        struct device_node *port_np;
        int port_id;

        for_each_child_of_node(ether_np, port_np) {
                /* It is not a 'port' node, continue. */
                if (strcmp(port_np->name, "port"))
                        continue;

                if (of_property_read_u32(port_np, "reg", &port_id) < 0)
                        continue;

                if (port_id == id)
                        return port_np;
        }

        /* Not found! */
        return NULL;
}

static int spl2sw_probe(struct platform_device *pdev)
{
        struct device_node *eth_ports_np;
        struct device_node *port_np;
        struct spl2sw_common *comm;
        struct device_node *phy_np;
        phy_interface_t phy_mode;
        struct net_device *ndev;
        struct spl2sw_mac *mac;
        u8 mac_addr[ETH_ALEN];
        int irq, i, ret;

        if (platform_get_drvdata(pdev))
                return -ENODEV;

        /* Allocate memory for 'spl2sw_common' area. */
        comm = devm_kzalloc(&pdev->dev, sizeof(*comm), GFP_KERNEL);
        if (!comm)
                return -ENOMEM;

        comm->pdev = pdev;
        platform_set_drvdata(pdev, comm);

        spin_lock_init(&comm->tx_lock);
        spin_lock_init(&comm->mdio_lock);
        spin_lock_init(&comm->int_mask_lock);

        /* Get memory resource 0 from dts. */
        comm->l2sw_reg_base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(comm->l2sw_reg_base))
                return PTR_ERR(comm->l2sw_reg_base);

        /* Get irq resource from dts. */
        ret = platform_get_irq(pdev, 0);
        if (ret < 0)
                return ret;
        irq = ret;

        /* Get clock controller. */
        comm->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(comm->clk)) {
                dev_err_probe(&pdev->dev, PTR_ERR(comm->clk),
                              "Failed to retrieve clock controller!\n");
                return PTR_ERR(comm->clk);
        }

        /* Get reset controller. */
        comm->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
        if (IS_ERR(comm->rstc)) {
                dev_err_probe(&pdev->dev, PTR_ERR(comm->rstc),
                              "Failed to retrieve reset controller!\n");
                return PTR_ERR(comm->rstc);
        }

        /* Enable clock. */
        ret = clk_prepare_enable(comm->clk);
        if (ret)
                return ret;
        udelay(1);

        /* Reset MAC */
        reset_control_assert(comm->rstc);
        udelay(1);
        reset_control_deassert(comm->rstc);
        usleep_range(1000, 2000);

        /* Request irq. */
        ret = devm_request_irq(&pdev->dev, irq, spl2sw_ethernet_interrupt, 0,
                               dev_name(&pdev->dev), comm);
        if (ret) {
                dev_err(&pdev->dev, "Failed to request irq #%d!\n", irq);
                goto out_clk_disable;
        }

        /* Initialize TX and RX descriptors. */
        ret = spl2sw_descs_init(comm);
        if (ret) {
                dev_err(&pdev->dev, "Fail to initialize mac descriptors!\n");
                spl2sw_descs_free(comm);
                goto out_clk_disable;
        }

        /* Initialize MAC. */
        spl2sw_mac_init(comm);

        /* Initialize mdio bus */
        ret = spl2sw_mdio_init(comm);
        if (ret) {
                dev_err(&pdev->dev, "Failed to initialize mdio bus!\n");
                goto out_clk_disable;
        }

        /* Get child node ethernet-ports. */
        eth_ports_np = of_get_child_by_name(pdev->dev.of_node, "ethernet-ports");
        if (!eth_ports_np) {
                dev_err(&pdev->dev, "No ethernet-ports child node found!\n");
                ret = -ENODEV;
                goto out_free_mdio;
        }

        for (i = 0; i < MAX_NETDEV_NUM; i++) {
                /* Get port@i of node ethernet-ports. */
                port_np = spl2sw_get_eth_child_node(eth_ports_np, i);
                if (!port_np)
                        continue;

                /* Get phy-mode. */
                if (of_get_phy_mode(port_np, &phy_mode)) {
                        dev_err(&pdev->dev, "Failed to get phy-mode property of port@%d!\n",
                                i);
                        continue;
                }

                /* Get phy-handle. */
                phy_np = of_parse_phandle(port_np, "phy-handle", 0);
                if (!phy_np) {
                        dev_err(&pdev->dev, "Failed to get phy-handle property of port@%d!\n",
                                i);
                        continue;
                }

                /* Get mac-address from nvmem. */
                ret = spl2sw_nvmem_get_mac_address(&pdev->dev, port_np, mac_addr);
                if (ret == -EPROBE_DEFER) {
                        goto out_unregister_dev;
                } else if (ret) {
                        dev_info(&pdev->dev, "Generate a random mac address!\n");
                        eth_random_addr(mac_addr);
                }

                /* Initialize the net device. */
                ret = spl2sw_init_netdev(pdev, mac_addr, &ndev);
                if (ret)
                        goto out_unregister_dev;

                ndev->irq = irq;
                comm->ndev[i] = ndev;
                mac = netdev_priv(ndev);
                mac->phy_node = phy_np;
                mac->phy_mode = phy_mode;
                mac->comm = comm;

                mac->lan_port = 0x1 << i;       /* forward to port i */
                mac->to_vlan = 0x1 << i;        /* vlan group: i     */
                mac->vlan_id = i;               /* vlan group: i     */

                /* Set MAC address */
                ret = spl2sw_mac_addr_add(mac);
                if (ret)
                        goto out_unregister_dev;

                spl2sw_mac_rx_mode_set(mac);
        }

        /* Find first valid net device. */
        for (i = 0; i < MAX_NETDEV_NUM; i++) {
                if (comm->ndev[i])
                        break;
        }
        if (i >= MAX_NETDEV_NUM) {
                dev_err(&pdev->dev, "No valid ethernet port!\n");
                ret = -ENODEV;
                goto out_free_mdio;
        }

        /* Save first valid net device */
        ndev = comm->ndev[i];

        ret = spl2sw_phy_connect(comm);
        if (ret) {
                netdev_err(ndev, "Failed to connect phy!\n");
                goto out_unregister_dev;
        }

        /* Add and enable napi. */
        netif_napi_add(ndev, &comm->rx_napi, spl2sw_rx_poll);
        napi_enable(&comm->rx_napi);
        netif_napi_add_tx(ndev, &comm->tx_napi, spl2sw_tx_poll);
        napi_enable(&comm->tx_napi);
        return 0;

out_unregister_dev:
        for (i = 0; i < MAX_NETDEV_NUM; i++)
                if (comm->ndev[i])
                        unregister_netdev(comm->ndev[i]);

out_free_mdio:
        spl2sw_mdio_remove(comm);

out_clk_disable:
        clk_disable_unprepare(comm->clk);
        return ret;
}

static void spl2sw_remove(struct platform_device *pdev)
{
        struct spl2sw_common *comm;
        int i;

        comm = platform_get_drvdata(pdev);

        spl2sw_phy_remove(comm);

        /* Unregister and free net device. */
        for (i = 0; i < MAX_NETDEV_NUM; i++)
                if (comm->ndev[i])
                        unregister_netdev(comm->ndev[i]);

        comm->enable = 0;
        spl2sw_mac_hw_stop(comm);
        spl2sw_descs_free(comm);

        /* Disable and delete napi. */
        napi_disable(&comm->rx_napi);
        netif_napi_del(&comm->rx_napi);
        napi_disable(&comm->tx_napi);
        netif_napi_del(&comm->tx_napi);

        spl2sw_mdio_remove(comm);

        clk_disable_unprepare(comm->clk);
}

static const struct of_device_id spl2sw_of_match[] = {
        {.compatible = "sunplus,sp7021-emac"},
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, spl2sw_of_match);

static struct platform_driver spl2sw_driver = {
        .probe = spl2sw_probe,
        .remove = spl2sw_remove,
        .driver = {
                .name = "sp7021_emac",
                .of_match_table = spl2sw_of_match,
        },
};

module_platform_driver(spl2sw_driver);

MODULE_AUTHOR("Wells Lu <wellslutw@gmail.com>");
MODULE_DESCRIPTION("Sunplus Dual 10M/100M Ethernet driver");
MODULE_LICENSE("GPL");