Merge tag 'powerpc-4.13-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...

[mirror_ubuntu-artful-kernel.git] / drivers / net / ethernet / qualcomm / emac / emac.c

/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

/* Qualcomm Technologies, Inc. EMAC Gigabit Ethernet Driver */

#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_net.h>
#include <linux/of_device.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include "emac.h"
#include "emac-mac.h"
#include "emac-phy.h"
#include "emac-sgmii.h"

#define EMAC_MSG_DEFAULT (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK |  \
                NETIF_MSG_TIMER | NETIF_MSG_IFDOWN | NETIF_MSG_IFUP)

#define EMAC_RRD_SIZE                                        4
/* The RRD size if timestamping is enabled: */
#define EMAC_TS_RRD_SIZE                                     6
#define EMAC_TPD_SIZE                                        4
#define EMAC_RFD_SIZE                                        2

#define REG_MAC_RX_STATUS_BIN            EMAC_RXMAC_STATC_REG0
#define REG_MAC_RX_STATUS_END           EMAC_RXMAC_STATC_REG22
#define REG_MAC_TX_STATUS_BIN            EMAC_TXMAC_STATC_REG0
#define REG_MAC_TX_STATUS_END           EMAC_TXMAC_STATC_REG24

#define RXQ0_NUM_RFD_PREF_DEF                                8
#define TXQ0_NUM_TPD_PREF_DEF                                5

#define EMAC_PREAMBLE_DEF                                    7

#define DMAR_DLY_CNT_DEF                                    15
#define DMAW_DLY_CNT_DEF                                     4

#define IMR_NORMAL_MASK         (ISR_ERROR | ISR_OVER | ISR_TX_PKT)

#define ISR_TX_PKT      (\
        TX_PKT_INT      |\
        TX_PKT_INT1     |\
        TX_PKT_INT2     |\
        TX_PKT_INT3)

#define ISR_OVER        (\
        RFD0_UR_INT     |\
        RFD1_UR_INT     |\
        RFD2_UR_INT     |\
        RFD3_UR_INT     |\
        RFD4_UR_INT     |\
        RXF_OF_INT      |\
        TXF_UR_INT)

#define ISR_ERROR       (\
        DMAR_TO_INT     |\
        DMAW_TO_INT     |\
        TXQ_TO_INT)

/* in sync with enum emac_clk_id */
static const char * const emac_clk_name[] = {
        "axi_clk", "cfg_ahb_clk", "high_speed_clk", "mdio_clk", "tx_clk",
        "rx_clk", "sys_clk"
};

void emac_reg_update32(void __iomem *addr, u32 mask, u32 val)
{
        u32 data = readl(addr);

        writel(((data & ~mask) | val), addr);
}

/* reinitialize */
int emac_reinit_locked(struct emac_adapter *adpt)
{
        int ret;

        mutex_lock(&adpt->reset_lock);

        emac_mac_down(adpt);
        emac_sgmii_reset(adpt);
        ret = emac_mac_up(adpt);

        mutex_unlock(&adpt->reset_lock);

        return ret;
}

/* NAPI */
static int emac_napi_rtx(struct napi_struct *napi, int budget)
{
        struct emac_rx_queue *rx_q =
                container_of(napi, struct emac_rx_queue, napi);
        struct emac_adapter *adpt = netdev_priv(rx_q->netdev);
        struct emac_irq *irq = rx_q->irq;
        int work_done = 0;

        emac_mac_rx_process(adpt, rx_q, &work_done, budget);

        if (work_done < budget) {
                napi_complete_done(napi, work_done);

                irq->mask |= rx_q->intr;
                writel(irq->mask, adpt->base + EMAC_INT_MASK);
        }

        return work_done;
}

/* Transmit the packet */
static int emac_start_xmit(struct sk_buff *skb, struct net_device *netdev)
{
        struct emac_adapter *adpt = netdev_priv(netdev);

        return emac_mac_tx_buf_send(adpt, &adpt->tx_q, skb);
}

irqreturn_t emac_isr(int _irq, void *data)
{
        struct emac_irq *irq = data;
        struct emac_adapter *adpt =
                container_of(irq, struct emac_adapter, irq);
        struct emac_rx_queue *rx_q = &adpt->rx_q;
        u32 isr, status;

        /* disable the interrupt */
        writel(0, adpt->base + EMAC_INT_MASK);

        isr = readl_relaxed(adpt->base + EMAC_INT_STATUS);

        status = isr & irq->mask;
        if (status == 0)
                goto exit;

        if (status & ISR_ERROR) {
                netif_warn(adpt,  intr, adpt->netdev,
                           "warning: error irq status 0x%lx\n",
                           status & ISR_ERROR);
                /* reset MAC */
                schedule_work(&adpt->work_thread);
        }

        /* Schedule the napi for receive queue with interrupt
         * status bit set
         */
        if (status & rx_q->intr) {
                if (napi_schedule_prep(&rx_q->napi)) {
                        irq->mask &= ~rx_q->intr;
                        __napi_schedule(&rx_q->napi);
                }
        }

        if (status & TX_PKT_INT)
                emac_mac_tx_process(adpt, &adpt->tx_q);

        if (status & ISR_OVER)
                net_warn_ratelimited("warning: TX/RX overflow\n");

exit:
        /* enable the interrupt */
        writel(irq->mask, adpt->base + EMAC_INT_MASK);

        return IRQ_HANDLED;
}

/* Configure VLAN tag strip/insert feature */
static int emac_set_features(struct net_device *netdev,
                             netdev_features_t features)
{
        netdev_features_t changed = features ^ netdev->features;
        struct emac_adapter *adpt = netdev_priv(netdev);

        /* We only need to reprogram the hardware if the VLAN tag features
         * have changed, and if it's already running.
         */
        if (!(changed & (NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX)))
                return 0;

        if (!netif_running(netdev))
                return 0;

        /* emac_mac_mode_config() uses netdev->features to configure the EMAC,
         * so make sure it's set first.
         */
        netdev->features = features;

        return emac_reinit_locked(adpt);
}

/* Configure Multicast and Promiscuous modes */
static void emac_rx_mode_set(struct net_device *netdev)
{
        struct emac_adapter *adpt = netdev_priv(netdev);
        struct netdev_hw_addr *ha;

        emac_mac_mode_config(adpt);

        /* update multicast address filtering */
        emac_mac_multicast_addr_clear(adpt);
        netdev_for_each_mc_addr(ha, netdev)
                emac_mac_multicast_addr_set(adpt, ha->addr);
}

/* Change the Maximum Transfer Unit (MTU) */
static int emac_change_mtu(struct net_device *netdev, int new_mtu)
{
        struct emac_adapter *adpt = netdev_priv(netdev);

        netif_info(adpt, hw, adpt->netdev,
                   "changing MTU from %d to %d\n", netdev->mtu,
                   new_mtu);
        netdev->mtu = new_mtu;

        if (netif_running(netdev))
                return emac_reinit_locked(adpt);

        return 0;
}

/* Called when the network interface is made active */
static int emac_open(struct net_device *netdev)
{
        struct emac_adapter *adpt = netdev_priv(netdev);
        struct emac_irq *irq = &adpt->irq;
        int ret;

        ret = request_irq(irq->irq, emac_isr, 0, "emac-core0", irq);
        if (ret) {
                netdev_err(adpt->netdev, "could not request emac-core0 irq\n");
                return ret;
        }

        /* allocate rx/tx dma buffer & descriptors */
        ret = emac_mac_rx_tx_rings_alloc_all(adpt);
        if (ret) {
                netdev_err(adpt->netdev, "error allocating rx/tx rings\n");
                free_irq(irq->irq, irq);
                return ret;
        }

        ret = emac_mac_up(adpt);
        if (ret) {
                emac_mac_rx_tx_rings_free_all(adpt);
                free_irq(irq->irq, irq);
                return ret;
        }

        ret = adpt->phy.open(adpt);
        if (ret) {
                emac_mac_down(adpt);
                emac_mac_rx_tx_rings_free_all(adpt);
                free_irq(irq->irq, irq);
                return ret;
        }

        return 0;
}

/* Called when the network interface is disabled */
static int emac_close(struct net_device *netdev)
{
        struct emac_adapter *adpt = netdev_priv(netdev);

        mutex_lock(&adpt->reset_lock);

        adpt->phy.close(adpt);
        emac_mac_down(adpt);
        emac_mac_rx_tx_rings_free_all(adpt);

        free_irq(adpt->irq.irq, &adpt->irq);

        mutex_unlock(&adpt->reset_lock);

        return 0;
}

/* Respond to a TX hang */
static void emac_tx_timeout(struct net_device *netdev)
{
        struct emac_adapter *adpt = netdev_priv(netdev);

        schedule_work(&adpt->work_thread);
}

/* IOCTL support for the interface */
static int emac_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
{
        if (!netif_running(netdev))
                return -EINVAL;

        if (!netdev->phydev)
                return -ENODEV;

        return phy_mii_ioctl(netdev->phydev, ifr, cmd);
}

/**
 * emac_update_hw_stats - read the EMAC stat registers
 *
 * Reads the stats registers and write the values to adpt->stats.
 *
 * adpt->stats.lock must be held while calling this function,
 * and while reading from adpt->stats.
 */
void emac_update_hw_stats(struct emac_adapter *adpt)
{
        struct emac_stats *stats = &adpt->stats;
        u64 *stats_itr = &adpt->stats.rx_ok;
        void __iomem *base = adpt->base;
        unsigned int addr;

        addr = REG_MAC_RX_STATUS_BIN;
        while (addr <= REG_MAC_RX_STATUS_END) {
                *stats_itr += readl_relaxed(base + addr);
                stats_itr++;
                addr += sizeof(u32);
        }

        /* additional rx status */
        stats->rx_crc_align += readl_relaxed(base + EMAC_RXMAC_STATC_REG23);
        stats->rx_jabbers += readl_relaxed(base + EMAC_RXMAC_STATC_REG24);

        /* update tx status */
        addr = REG_MAC_TX_STATUS_BIN;
        stats_itr = &stats->tx_ok;

        while (addr <= REG_MAC_TX_STATUS_END) {
                *stats_itr += readl_relaxed(base + addr);
                stats_itr++;
                addr += sizeof(u32);
        }

        /* additional tx status */
        stats->tx_col += readl_relaxed(base + EMAC_TXMAC_STATC_REG25);
}

/* Provide network statistics info for the interface */
static void emac_get_stats64(struct net_device *netdev,
                             struct rtnl_link_stats64 *net_stats)
{
        struct emac_adapter *adpt = netdev_priv(netdev);
        struct emac_stats *stats = &adpt->stats;

        spin_lock(&stats->lock);

        emac_update_hw_stats(adpt);

        /* return parsed statistics */
        net_stats->rx_packets = stats->rx_ok;
        net_stats->tx_packets = stats->tx_ok;
        net_stats->rx_bytes = stats->rx_byte_cnt;
        net_stats->tx_bytes = stats->tx_byte_cnt;
        net_stats->multicast = stats->rx_mcast;
        net_stats->collisions = stats->tx_1_col + stats->tx_2_col * 2 +
                                stats->tx_late_col + stats->tx_abort_col;

        net_stats->rx_errors = stats->rx_frag + stats->rx_fcs_err +
                               stats->rx_len_err + stats->rx_sz_ov +
                               stats->rx_align_err;
        net_stats->rx_fifo_errors = stats->rx_rxf_ov;
        net_stats->rx_length_errors = stats->rx_len_err;
        net_stats->rx_crc_errors = stats->rx_fcs_err;
        net_stats->rx_frame_errors = stats->rx_align_err;
        net_stats->rx_over_errors = stats->rx_rxf_ov;
        net_stats->rx_missed_errors = stats->rx_rxf_ov;

        net_stats->tx_errors = stats->tx_late_col + stats->tx_abort_col +
                               stats->tx_underrun + stats->tx_trunc;
        net_stats->tx_fifo_errors = stats->tx_underrun;
        net_stats->tx_aborted_errors = stats->tx_abort_col;
        net_stats->tx_window_errors = stats->tx_late_col;

        spin_unlock(&stats->lock);
}

static const struct net_device_ops emac_netdev_ops = {
        .ndo_open               = emac_open,
        .ndo_stop               = emac_close,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_start_xmit         = emac_start_xmit,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_change_mtu         = emac_change_mtu,
        .ndo_do_ioctl           = emac_ioctl,
        .ndo_tx_timeout         = emac_tx_timeout,
        .ndo_get_stats64        = emac_get_stats64,
        .ndo_set_features       = emac_set_features,
        .ndo_set_rx_mode        = emac_rx_mode_set,
};

/* Watchdog task routine, called to reinitialize the EMAC */
static void emac_work_thread(struct work_struct *work)
{
        struct emac_adapter *adpt =
                container_of(work, struct emac_adapter, work_thread);

        emac_reinit_locked(adpt);
}

/* Initialize various data structures  */
static void emac_init_adapter(struct emac_adapter *adpt)
{
        u32 reg;

        adpt->rrd_size = EMAC_RRD_SIZE;
        adpt->tpd_size = EMAC_TPD_SIZE;
        adpt->rfd_size = EMAC_RFD_SIZE;

        /* descriptors */
        adpt->tx_desc_cnt = EMAC_DEF_TX_DESCS;
        adpt->rx_desc_cnt = EMAC_DEF_RX_DESCS;

        /* dma */
        adpt->dma_order = emac_dma_ord_out;
        adpt->dmar_block = emac_dma_req_4096;
        adpt->dmaw_block = emac_dma_req_128;
        adpt->dmar_dly_cnt = DMAR_DLY_CNT_DEF;
        adpt->dmaw_dly_cnt = DMAW_DLY_CNT_DEF;
        adpt->tpd_burst = TXQ0_NUM_TPD_PREF_DEF;
        adpt->rfd_burst = RXQ0_NUM_RFD_PREF_DEF;

        /* irq moderator */
        reg = ((EMAC_DEF_RX_IRQ_MOD >> 1) << IRQ_MODERATOR2_INIT_SHFT) |
              ((EMAC_DEF_TX_IRQ_MOD >> 1) << IRQ_MODERATOR_INIT_SHFT);
        adpt->irq_mod = reg;

        /* others */
        adpt->preamble = EMAC_PREAMBLE_DEF;

        /* default to automatic flow control */
        adpt->automatic = true;
}

/* Get the clock */
static int emac_clks_get(struct platform_device *pdev,
                         struct emac_adapter *adpt)
{
        unsigned int i;

        for (i = 0; i < EMAC_CLK_CNT; i++) {
                struct clk *clk = devm_clk_get(&pdev->dev, emac_clk_name[i]);

                if (IS_ERR(clk)) {
                        dev_err(&pdev->dev,
                                "could not claim clock %s (error=%li)\n",
                                emac_clk_name[i], PTR_ERR(clk));

                        return PTR_ERR(clk);
                }

                adpt->clk[i] = clk;
        }

        return 0;
}

/* Initialize clocks */
static int emac_clks_phase1_init(struct platform_device *pdev,
                                 struct emac_adapter *adpt)
{
        int ret;

        /* On ACPI platforms, clocks are controlled by firmware and/or
         * ACPI, not by drivers.
         */
        if (has_acpi_companion(&pdev->dev))
                return 0;

        ret = emac_clks_get(pdev, adpt);
        if (ret)
                return ret;

        ret = clk_prepare_enable(adpt->clk[EMAC_CLK_AXI]);
        if (ret)
                return ret;

        ret = clk_prepare_enable(adpt->clk[EMAC_CLK_CFG_AHB]);
        if (ret)
                return ret;

        ret = clk_set_rate(adpt->clk[EMAC_CLK_HIGH_SPEED], 19200000);
        if (ret)
                return ret;

        return clk_prepare_enable(adpt->clk[EMAC_CLK_HIGH_SPEED]);
}

/* Enable clocks; needs emac_clks_phase1_init to be called before */
static int emac_clks_phase2_init(struct platform_device *pdev,
                                 struct emac_adapter *adpt)
{
        int ret;

        if (has_acpi_companion(&pdev->dev))
                return 0;

        ret = clk_set_rate(adpt->clk[EMAC_CLK_TX], 125000000);
        if (ret)
                return ret;

        ret = clk_prepare_enable(adpt->clk[EMAC_CLK_TX]);
        if (ret)
                return ret;

        ret = clk_set_rate(adpt->clk[EMAC_CLK_HIGH_SPEED], 125000000);
        if (ret)
                return ret;

        ret = clk_set_rate(adpt->clk[EMAC_CLK_MDIO], 25000000);
        if (ret)
                return ret;

        ret = clk_prepare_enable(adpt->clk[EMAC_CLK_MDIO]);
        if (ret)
                return ret;

        ret = clk_prepare_enable(adpt->clk[EMAC_CLK_RX]);
        if (ret)
                return ret;

        return clk_prepare_enable(adpt->clk[EMAC_CLK_SYS]);
}

static void emac_clks_teardown(struct emac_adapter *adpt)
{

        unsigned int i;

        for (i = 0; i < EMAC_CLK_CNT; i++)
                clk_disable_unprepare(adpt->clk[i]);
}

/* Get the resources */
static int emac_probe_resources(struct platform_device *pdev,
                                struct emac_adapter *adpt)
{
        struct net_device *netdev = adpt->netdev;
        struct resource *res;
        char maddr[ETH_ALEN];
        int ret = 0;

        /* get mac address */
        if (device_get_mac_address(&pdev->dev, maddr, ETH_ALEN))
                ether_addr_copy(netdev->dev_addr, maddr);
        else
                eth_hw_addr_random(netdev);

        /* Core 0 interrupt */
        ret = platform_get_irq(pdev, 0);
        if (ret < 0) {
                dev_err(&pdev->dev,
                        "error: missing core0 irq resource (error=%i)\n", ret);
                return ret;
        }
        adpt->irq.irq = ret;

        /* base register address */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        adpt->base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(adpt->base))
                return PTR_ERR(adpt->base);

        /* CSR register address */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        adpt->csr = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(adpt->csr))
                return PTR_ERR(adpt->csr);

        netdev->base_addr = (unsigned long)adpt->base;

        return 0;
}

static const struct of_device_id emac_dt_match[] = {
        {
                .compatible = "qcom,fsm9900-emac",
        },
        {}
};
MODULE_DEVICE_TABLE(of, emac_dt_match);

#if IS_ENABLED(CONFIG_ACPI)
static const struct acpi_device_id emac_acpi_match[] = {
        {
                .id = "QCOM8070",
        },
        {}
};
MODULE_DEVICE_TABLE(acpi, emac_acpi_match);
#endif

static int emac_probe(struct platform_device *pdev)
{
        struct net_device *netdev;
        struct emac_adapter *adpt;
        struct emac_sgmii *phy;
        u16 devid, revid;
        u32 reg;
        int ret;

        /* The EMAC itself is capable of 64-bit DMA, so try that first. */
        ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
        if (ret) {
                /* Some platforms may restrict the EMAC's address bus to less
                 * then the size of DDR. In this case, we need to try a
                 * smaller mask.  We could try every possible smaller mask,
                 * but that's overkill.  Instead, just fall to 32-bit, which
                 * should always work.
                 */
                ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
                if (ret) {
                        dev_err(&pdev->dev, "could not set DMA mask\n");
                        return ret;
                }
        }

        netdev = alloc_etherdev(sizeof(struct emac_adapter));
        if (!netdev)
                return -ENOMEM;

        dev_set_drvdata(&pdev->dev, netdev);
        SET_NETDEV_DEV(netdev, &pdev->dev);
        emac_set_ethtool_ops(netdev);

        adpt = netdev_priv(netdev);
        adpt->netdev = netdev;
        adpt->msg_enable = EMAC_MSG_DEFAULT;

        phy = &adpt->phy;
        atomic_set(&phy->decode_error_count, 0);

        mutex_init(&adpt->reset_lock);
        spin_lock_init(&adpt->stats.lock);

        adpt->irq.mask = RX_PKT_INT0 | IMR_NORMAL_MASK;

        ret = emac_probe_resources(pdev, adpt);
        if (ret)
                goto err_undo_netdev;

        /* initialize clocks */
        ret = emac_clks_phase1_init(pdev, adpt);
        if (ret) {
                dev_err(&pdev->dev, "could not initialize clocks\n");
                goto err_undo_netdev;
        }

        netdev->watchdog_timeo = EMAC_WATCHDOG_TIME;
        netdev->irq = adpt->irq.irq;

        netdev->netdev_ops = &emac_netdev_ops;

        emac_init_adapter(adpt);

        /* init external phy */
        ret = emac_phy_config(pdev, adpt);
        if (ret)
                goto err_undo_clocks;

        /* init internal sgmii phy */
        ret = emac_sgmii_config(pdev, adpt);
        if (ret)
                goto err_undo_mdiobus;

        /* enable clocks */
        ret = emac_clks_phase2_init(pdev, adpt);
        if (ret) {
                dev_err(&pdev->dev, "could not initialize clocks\n");
                goto err_undo_mdiobus;
        }

        /* set hw features */
        netdev->features = NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM |
                        NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_HW_VLAN_CTAG_RX |
                        NETIF_F_HW_VLAN_CTAG_TX;
        netdev->hw_features = netdev->features;

        netdev->vlan_features |= NETIF_F_SG | NETIF_F_HW_CSUM |
                                 NETIF_F_TSO | NETIF_F_TSO6;

        /* MTU range: 46 - 9194 */
        netdev->min_mtu = EMAC_MIN_ETH_FRAME_SIZE -
                          (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
        netdev->max_mtu = EMAC_MAX_ETH_FRAME_SIZE -
                          (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);

        INIT_WORK(&adpt->work_thread, emac_work_thread);

        /* Initialize queues */
        emac_mac_rx_tx_ring_init_all(pdev, adpt);

        netif_napi_add(netdev, &adpt->rx_q.napi, emac_napi_rtx,
                       NAPI_POLL_WEIGHT);

        ret = register_netdev(netdev);
        if (ret) {
                dev_err(&pdev->dev, "could not register net device\n");
                goto err_undo_napi;
        }

        reg =  readl_relaxed(adpt->base + EMAC_DMA_MAS_CTRL);
        devid = (reg & DEV_ID_NUM_BMSK)  >> DEV_ID_NUM_SHFT;
        revid = (reg & DEV_REV_NUM_BMSK) >> DEV_REV_NUM_SHFT;
        reg = readl_relaxed(adpt->base + EMAC_CORE_HW_VERSION);

        netif_info(adpt, probe, netdev,
                   "hardware id %d.%d, hardware version %d.%d.%d\n",
                   devid, revid,
                   (reg & MAJOR_BMSK) >> MAJOR_SHFT,
                   (reg & MINOR_BMSK) >> MINOR_SHFT,
                   (reg & STEP_BMSK)  >> STEP_SHFT);

        return 0;

err_undo_napi:
        netif_napi_del(&adpt->rx_q.napi);
err_undo_mdiobus:
        put_device(&adpt->phydev->mdio.dev);
        mdiobus_unregister(adpt->mii_bus);
err_undo_clocks:
        emac_clks_teardown(adpt);
err_undo_netdev:
        free_netdev(netdev);

        return ret;
}

static int emac_remove(struct platform_device *pdev)
{
        struct net_device *netdev = dev_get_drvdata(&pdev->dev);
        struct emac_adapter *adpt = netdev_priv(netdev);

        unregister_netdev(netdev);
        netif_napi_del(&adpt->rx_q.napi);

        emac_clks_teardown(adpt);

        put_device(&adpt->phydev->mdio.dev);
        mdiobus_unregister(adpt->mii_bus);
        free_netdev(netdev);

        if (adpt->phy.digital)
                iounmap(adpt->phy.digital);
        iounmap(adpt->phy.base);

        return 0;
}

static void emac_shutdown(struct platform_device *pdev)
{
        struct net_device *netdev = dev_get_drvdata(&pdev->dev);
        struct emac_adapter *adpt = netdev_priv(netdev);
        struct emac_sgmii *sgmii = &adpt->phy;

        if (netdev->flags & IFF_UP) {
                /* Closing the SGMII turns off its interrupts */
                sgmii->close(adpt);

                /* Resetting the MAC turns off all DMA and its interrupts */
                emac_mac_reset(adpt);
        }
}

static struct platform_driver emac_platform_driver = {
        .probe  = emac_probe,
        .remove = emac_remove,
        .driver = {
                .name           = "qcom-emac",
                .of_match_table = emac_dt_match,
                .acpi_match_table = ACPI_PTR(emac_acpi_match),
        },
        .shutdown = emac_shutdown,
};

module_platform_driver(emac_platform_driver);

MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:qcom-emac");