[linux-block.git] / drivers / net / ethernet / lantiq_xrx200.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Lantiq / Intel PMAC driver for XRX200 SoCs
 *
 * Copyright (C) 2010 Lantiq Deutschland
 * Copyright (C) 2012 John Crispin <john@phrozen.org>
 * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
 */

#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/delay.h>

#include <linux/if_vlan.h>

#include <linux/of_net.h>
#include <linux/of_platform.h>

#include <xway_dma.h>

/* DMA */
#define XRX200_DMA_DATA_LEN	(SZ_64K - 1)
#define XRX200_DMA_RX		0
#define XRX200_DMA_TX		1
#define XRX200_DMA_BURST_LEN	8

#define XRX200_DMA_PACKET_COMPLETE	0
#define XRX200_DMA_PACKET_IN_PROGRESS	1

/* cpu port mac */
#define PMAC_RX_IPG		0x0024
#define PMAC_RX_IPG_MASK	0xf

#define PMAC_HD_CTL		0x0000
/* Add Ethernet header to packets from DMA to PMAC */
#define PMAC_HD_CTL_ADD		BIT(0)
/* Add VLAN tag to Packets from DMA to PMAC */
#define PMAC_HD_CTL_TAG		BIT(1)
/* Add CRC to packets from DMA to PMAC */
#define PMAC_HD_CTL_AC		BIT(2)
/* Add status header to packets from PMAC to DMA */
#define PMAC_HD_CTL_AS		BIT(3)
/* Remove CRC from packets from PMAC to DMA */
#define PMAC_HD_CTL_RC		BIT(4)
/* Remove Layer-2 header from packets from PMAC to DMA */
#define PMAC_HD_CTL_RL2		BIT(5)
/* Status header is present from DMA to PMAC */
#define PMAC_HD_CTL_RXSH	BIT(6)
/* Add special tag from PMAC to switch */
#define PMAC_HD_CTL_AST		BIT(7)
/* Remove specail Tag from PMAC to DMA */
#define PMAC_HD_CTL_RST		BIT(8)
/* Check CRC from DMA to PMAC */
#define PMAC_HD_CTL_CCRC	BIT(9)
/* Enable reaction to Pause frames in the PMAC */
#define PMAC_HD_CTL_FC		BIT(10)

struct xrx200_chan {
	int tx_free;

	struct napi_struct napi;
	struct ltq_dma_channel dma;

	union {
		struct sk_buff *skb[LTQ_DESC_NUM];
		void *rx_buff[LTQ_DESC_NUM];
	};

	struct sk_buff *skb_head;
	struct sk_buff *skb_tail;

	struct xrx200_priv *priv;
};

struct xrx200_priv {
	struct clk *clk;

	struct xrx200_chan chan_tx;
	struct xrx200_chan chan_rx;

	u16 rx_buf_size;
	u16 rx_skb_size;

	struct net_device *net_dev;
	struct device *dev;

	__iomem void *pmac_reg;
};

static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset)
{
	return __raw_readl(priv->pmac_reg + offset);
}

static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset)
{
	__raw_writel(val, priv->pmac_reg + offset);
}

static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
			     u32 offset)
{
	u32 val = xrx200_pmac_r32(priv, offset);

	val &= ~(clear);
	val |= set;
	xrx200_pmac_w32(priv, val, offset);
}

static int xrx200_max_frame_len(int mtu)
{
	return VLAN_ETH_HLEN + mtu;
}

static int xrx200_buffer_size(int mtu)
{
	return round_up(xrx200_max_frame_len(mtu), 4 * XRX200_DMA_BURST_LEN);
}

static int xrx200_skb_size(u16 buf_size)
{
	return SKB_DATA_ALIGN(buf_size + NET_SKB_PAD + NET_IP_ALIGN) +
		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
}

/* drop all the packets from the DMA ring */
static void xrx200_flush_dma(struct xrx200_chan *ch)
{
	int i;

	for (i = 0; i < LTQ_DESC_NUM; i++) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) != LTQ_DMA_C)
			break;

		desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
			    ch->priv->rx_buf_size;
		ch->dma.desc++;
		ch->dma.desc %= LTQ_DESC_NUM;
	}
}

static int xrx200_open(struct net_device *net_dev)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);

	napi_enable(&priv->chan_tx.napi);
	ltq_dma_open(&priv->chan_tx.dma);
	ltq_dma_enable_irq(&priv->chan_tx.dma);

	napi_enable(&priv->chan_rx.napi);
	ltq_dma_open(&priv->chan_rx.dma);
	/* The boot loader does not always deactivate the receiving of frames
	 * on the ports and then some packets queue up in the PPE buffers.
	 * They already passed the PMAC so they do not have the tags
	 * configured here. Read the these packets here and drop them.
	 * The HW should have written them into memory after 10us
	 */
	usleep_range(20, 40);
	xrx200_flush_dma(&priv->chan_rx);
	ltq_dma_enable_irq(&priv->chan_rx.dma);

	netif_wake_queue(net_dev);

	return 0;
}

static int xrx200_close(struct net_device *net_dev)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);

	netif_stop_queue(net_dev);

	napi_disable(&priv->chan_rx.napi);
	ltq_dma_close(&priv->chan_rx.dma);

	napi_disable(&priv->chan_tx.napi);
	ltq_dma_close(&priv->chan_tx.dma);

	return 0;
}

static int xrx200_alloc_buf(struct xrx200_chan *ch, void *(*alloc)(unsigned int size))
{
	void *buf = ch->rx_buff[ch->dma.desc];
	struct xrx200_priv *priv = ch->priv;
	dma_addr_t mapping;
	int ret = 0;

	ch->rx_buff[ch->dma.desc] = alloc(priv->rx_skb_size);
	if (!ch->rx_buff[ch->dma.desc]) {
		ch->rx_buff[ch->dma.desc] = buf;
		ret = -ENOMEM;
		goto skip;
	}

	mapping = dma_map_single(priv->dev, ch->rx_buff[ch->dma.desc],
				 priv->rx_buf_size, DMA_FROM_DEVICE);
	if (unlikely(dma_mapping_error(priv->dev, mapping))) {
		skb_free_frag(ch->rx_buff[ch->dma.desc]);
		ch->rx_buff[ch->dma.desc] = buf;
		ret = -ENOMEM;
		goto skip;
	}

	ch->dma.desc_base[ch->dma.desc].addr = mapping + NET_SKB_PAD + NET_IP_ALIGN;
	/* Make sure the address is written before we give it to HW */
	wmb();
skip:
	ch->dma.desc_base[ch->dma.desc].ctl =
		LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | priv->rx_buf_size;

	return ret;
}

static int xrx200_hw_receive(struct xrx200_chan *ch)
{
	struct xrx200_priv *priv = ch->priv;
	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	void *buf = ch->rx_buff[ch->dma.desc];
	u32 ctl = desc->ctl;
	int len = (ctl & LTQ_DMA_SIZE_MASK);
	struct net_device *net_dev = priv->net_dev;
	struct sk_buff *skb;
	int ret;

	ret = xrx200_alloc_buf(ch, napi_alloc_frag);

	ch->dma.desc++;
	ch->dma.desc %= LTQ_DESC_NUM;

	if (ret) {
		net_dev->stats.rx_dropped++;
		netdev_err(net_dev, "failed to allocate new rx buffer\n");
		return ret;
	}

	skb = build_skb(buf, priv->rx_skb_size);
	if (!skb) {
		skb_free_frag(buf);
		net_dev->stats.rx_dropped++;
		return -ENOMEM;
	}

	skb_reserve(skb, NET_SKB_PAD);
	skb_put(skb, len);

	/* add buffers to skb via skb->frag_list */
	if (ctl & LTQ_DMA_SOP) {
		ch->skb_head = skb;
		ch->skb_tail = skb;
		skb_reserve(skb, NET_IP_ALIGN);
	} else if (ch->skb_head) {
		if (ch->skb_head == ch->skb_tail)
			skb_shinfo(ch->skb_tail)->frag_list = skb;
		else
			ch->skb_tail->next = skb;
		ch->skb_tail = skb;
		ch->skb_head->len += skb->len;
		ch->skb_head->data_len += skb->len;
		ch->skb_head->truesize += skb->truesize;
	}

	if (ctl & LTQ_DMA_EOP) {
		ch->skb_head->protocol = eth_type_trans(ch->skb_head, net_dev);
		net_dev->stats.rx_packets++;
		net_dev->stats.rx_bytes += ch->skb_head->len;
		netif_receive_skb(ch->skb_head);
		ch->skb_head = NULL;
		ch->skb_tail = NULL;
		ret = XRX200_DMA_PACKET_COMPLETE;
	} else {
		ret = XRX200_DMA_PACKET_IN_PROGRESS;
	}

	return ret;
}

static int xrx200_poll_rx(struct napi_struct *napi, int budget)
{
	struct xrx200_chan *ch = container_of(napi,
				struct xrx200_chan, napi);
	int rx = 0;
	int ret;

	while (rx < budget) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
			ret = xrx200_hw_receive(ch);
			if (ret == XRX200_DMA_PACKET_IN_PROGRESS)
				continue;
			if (ret != XRX200_DMA_PACKET_COMPLETE)
				break;
			rx++;
		} else {
			break;
		}
	}

	if (rx < budget) {
		if (napi_complete_done(&ch->napi, rx))
			ltq_dma_enable_irq(&ch->dma);
	}

	return rx;
}

static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
{
	struct xrx200_chan *ch = container_of(napi,
				struct xrx200_chan, napi);
	struct net_device *net_dev = ch->priv->net_dev;
	int pkts = 0;
	int bytes = 0;

	netif_tx_lock(net_dev);
	while (pkts < budget) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
			struct sk_buff *skb = ch->skb[ch->tx_free];

			pkts++;
			bytes += skb->len;
			ch->skb[ch->tx_free] = NULL;
			consume_skb(skb);
			memset(&ch->dma.desc_base[ch->tx_free], 0,
			       sizeof(struct ltq_dma_desc));
			ch->tx_free++;
			ch->tx_free %= LTQ_DESC_NUM;
		} else {
			break;
		}
	}

	net_dev->stats.tx_packets += pkts;
	net_dev->stats.tx_bytes += bytes;
	netdev_completed_queue(ch->priv->net_dev, pkts, bytes);

	netif_tx_unlock(net_dev);
	if (netif_queue_stopped(net_dev))
		netif_wake_queue(net_dev);

	if (pkts < budget) {
		if (napi_complete_done(&ch->napi, pkts))
			ltq_dma_enable_irq(&ch->dma);
	}

	return pkts;
}

static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
				     struct net_device *net_dev)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);
	struct xrx200_chan *ch = &priv->chan_tx;
	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	u32 byte_offset;
	dma_addr_t mapping;
	int len;

	skb->dev = net_dev;
	if (skb_put_padto(skb, ETH_ZLEN)) {
		net_dev->stats.tx_dropped++;
		return NETDEV_TX_OK;
	}

	len = skb->len;

	if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
		netdev_err(net_dev, "tx ring full\n");
		netif_stop_queue(net_dev);
		return NETDEV_TX_BUSY;
	}

	ch->skb[ch->dma.desc] = skb;

	mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
	if (unlikely(dma_mapping_error(priv->dev, mapping)))
		goto err_drop;

	/* dma needs to start on a burst length value aligned address */
	byte_offset = mapping % (XRX200_DMA_BURST_LEN * 4);

	desc->addr = mapping - byte_offset;
	/* Make sure the address is written before we give it to HW */
	wmb();
	desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
		LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
	ch->dma.desc++;
	ch->dma.desc %= LTQ_DESC_NUM;
	if (ch->dma.desc == ch->tx_free)
		netif_stop_queue(net_dev);

	netdev_sent_queue(net_dev, len);

	return NETDEV_TX_OK;

err_drop:
	dev_kfree_skb(skb);
	net_dev->stats.tx_dropped++;
	net_dev->stats.tx_errors++;
	return NETDEV_TX_OK;
}

static int
xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);
	struct xrx200_chan *ch_rx = &priv->chan_rx;
	int old_mtu = net_dev->mtu;
	bool running = false;
	void *buff;
	int curr_desc;
	int ret = 0;

	WRITE_ONCE(net_dev->mtu, new_mtu);
	priv->rx_buf_size = xrx200_buffer_size(new_mtu);
	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);

	if (new_mtu <= old_mtu)
		return ret;

	running = netif_running(net_dev);
	if (running) {
		napi_disable(&ch_rx->napi);
		ltq_dma_close(&ch_rx->dma);
	}

	xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
	curr_desc = ch_rx->dma.desc;

	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
	     ch_rx->dma.desc++) {
		buff = ch_rx->rx_buff[ch_rx->dma.desc];
		ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
		if (ret) {
			WRITE_ONCE(net_dev->mtu, old_mtu);
			priv->rx_buf_size = xrx200_buffer_size(old_mtu);
			priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
			break;
		}
		skb_free_frag(buff);
	}

	ch_rx->dma.desc = curr_desc;
	if (running) {
		napi_enable(&ch_rx->napi);
		ltq_dma_open(&ch_rx->dma);
		ltq_dma_enable_irq(&ch_rx->dma);
	}

	return ret;
}

static const struct net_device_ops xrx200_netdev_ops = {
	.ndo_open		= xrx200_open,
	.ndo_stop		= xrx200_close,
	.ndo_start_xmit		= xrx200_start_xmit,
	.ndo_change_mtu		= xrx200_change_mtu,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};

static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
{
	struct xrx200_chan *ch = ptr;

	if (napi_schedule_prep(&ch->napi)) {
		ltq_dma_disable_irq(&ch->dma);
		__napi_schedule(&ch->napi);
	}

	ltq_dma_ack_irq(&ch->dma);

	return IRQ_HANDLED;
}

static int xrx200_dma_init(struct xrx200_priv *priv)
{
	struct xrx200_chan *ch_rx = &priv->chan_rx;
	struct xrx200_chan *ch_tx = &priv->chan_tx;
	int ret = 0;
	int i;

	ltq_dma_init_port(DMA_PORT_ETOP, XRX200_DMA_BURST_LEN,
			  XRX200_DMA_BURST_LEN);

	ch_rx->dma.nr = XRX200_DMA_RX;
	ch_rx->dma.dev = priv->dev;
	ch_rx->priv = priv;

	ltq_dma_alloc_rx(&ch_rx->dma);
	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
	     ch_rx->dma.desc++) {
		ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
		if (ret)
			goto rx_free;
	}
	ch_rx->dma.desc = 0;
	ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
			       "xrx200_net_rx", &priv->chan_rx);
	if (ret) {
		dev_err(priv->dev, "failed to request RX irq %d\n",
			ch_rx->dma.irq);
		goto rx_ring_free;
	}

	ch_tx->dma.nr = XRX200_DMA_TX;
	ch_tx->dma.dev = priv->dev;
	ch_tx->priv = priv;

	ltq_dma_alloc_tx(&ch_tx->dma);
	ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
			       "xrx200_net_tx", &priv->chan_tx);
	if (ret) {
		dev_err(priv->dev, "failed to request TX irq %d\n",
			ch_tx->dma.irq);
		goto tx_free;
	}

	return ret;

tx_free:
	ltq_dma_free(&ch_tx->dma);

rx_ring_free:
	/* free the allocated RX ring */
	for (i = 0; i < LTQ_DESC_NUM; i++) {
		if (priv->chan_rx.skb[i])
			skb_free_frag(priv->chan_rx.rx_buff[i]);
	}

rx_free:
	ltq_dma_free(&ch_rx->dma);
	return ret;
}

static void xrx200_hw_cleanup(struct xrx200_priv *priv)
{
	int i;

	ltq_dma_free(&priv->chan_tx.dma);
	ltq_dma_free(&priv->chan_rx.dma);

	/* free the allocated RX ring */
	for (i = 0; i < LTQ_DESC_NUM; i++)
		skb_free_frag(priv->chan_rx.rx_buff[i]);
}

static int xrx200_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct xrx200_priv *priv;
	struct net_device *net_dev;
	int err;

	/* alloc the network device */
	net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
	if (!net_dev)
		return -ENOMEM;

	priv = netdev_priv(net_dev);
	priv->net_dev = net_dev;
	priv->dev = dev;

	net_dev->netdev_ops = &xrx200_netdev_ops;
	SET_NETDEV_DEV(net_dev, dev);
	net_dev->min_mtu = ETH_ZLEN;
	net_dev->max_mtu = XRX200_DMA_DATA_LEN - xrx200_max_frame_len(0);
	priv->rx_buf_size = xrx200_buffer_size(ETH_DATA_LEN);
	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);

	/* load the memory ranges */
	priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
	if (IS_ERR(priv->pmac_reg))
		return PTR_ERR(priv->pmac_reg);

	priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
	if (priv->chan_rx.dma.irq < 0)
		return -ENOENT;
	priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
	if (priv->chan_tx.dma.irq < 0)
		return -ENOENT;

	/* get the clock */
	priv->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(priv->clk)) {
		dev_err(dev, "failed to get clock\n");
		return PTR_ERR(priv->clk);
	}

	err = of_get_ethdev_address(np, net_dev);
	if (err)
		eth_hw_addr_random(net_dev);

	/* bring up the dma engine and IP core */
	err = xrx200_dma_init(priv);
	if (err)
		return err;

	/* enable clock gate */
	err = clk_prepare_enable(priv->clk);
	if (err)
		goto err_uninit_dma;

	/* set IPG to 12 */
	xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);

	/* enable status header, enable CRC */
	xrx200_pmac_mask(priv, 0,
			 PMAC_HD_CTL_RST | PMAC_HD_CTL_AST | PMAC_HD_CTL_RXSH |
			 PMAC_HD_CTL_AS | PMAC_HD_CTL_AC | PMAC_HD_CTL_RC,
			 PMAC_HD_CTL);

	/* setup NAPI */
	netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx);
	netif_napi_add_tx(net_dev, &priv->chan_tx.napi,
			  xrx200_tx_housekeeping);

	platform_set_drvdata(pdev, priv);

	err = register_netdev(net_dev);
	if (err)
		goto err_unprepare_clk;

	return 0;

err_unprepare_clk:
	clk_disable_unprepare(priv->clk);

err_uninit_dma:
	xrx200_hw_cleanup(priv);

	return err;
}

static void xrx200_remove(struct platform_device *pdev)
{
	struct xrx200_priv *priv = platform_get_drvdata(pdev);
	struct net_device *net_dev = priv->net_dev;

	/* free stack related instances */
	netif_stop_queue(net_dev);
	netif_napi_del(&priv->chan_tx.napi);
	netif_napi_del(&priv->chan_rx.napi);

	/* remove the actual device */
	unregister_netdev(net_dev);

	/* release the clock */
	clk_disable_unprepare(priv->clk);

	/* shut down hardware */
	xrx200_hw_cleanup(priv);
}

static const struct of_device_id xrx200_match[] = {
	{ .compatible = "lantiq,xrx200-net" },
	{},
};
MODULE_DEVICE_TABLE(of, xrx200_match);

static struct platform_driver xrx200_driver = {
	.probe = xrx200_probe,
	.remove = xrx200_remove,
	.driver = {
		.name = "lantiq,xrx200-net",
		.of_match_table = xrx200_match,
	},
};

module_platform_driver(xrx200_driver);

MODULE_AUTHOR("John Crispin <john@phrozen.org>");
MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Lantiq / Intel PMAC driver for XRX200 SoCs
	4	*
	5	* Copyright (C) 2010 Lantiq Deutschland
	6	* Copyright (C) 2012 John Crispin <john@phrozen.org>
	7	* Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
	8	*/
	9
	10	#include <linux/etherdevice.h>
	11	#include <linux/module.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/clk.h>
	15	#include <linux/delay.h>
	16
	17	#include <linux/if_vlan.h>
	18
	19	#include <linux/of_net.h>
	20	#include <linux/of_platform.h>
	21
	22	#include <xway_dma.h>
	23
	24	/* DMA */
	25	#define XRX200_DMA_DATA_LEN (SZ_64K - 1)
	26	#define XRX200_DMA_RX 0
	27	#define XRX200_DMA_TX 1
	28	#define XRX200_DMA_BURST_LEN 8
	29
	30	#define XRX200_DMA_PACKET_COMPLETE 0
	31	#define XRX200_DMA_PACKET_IN_PROGRESS 1
	32
	33	/* cpu port mac */
	34	#define PMAC_RX_IPG 0x0024
	35	#define PMAC_RX_IPG_MASK 0xf
	36
	37	#define PMAC_HD_CTL 0x0000
	38	/* Add Ethernet header to packets from DMA to PMAC */
	39	#define PMAC_HD_CTL_ADD BIT(0)
	40	/* Add VLAN tag to Packets from DMA to PMAC */
	41	#define PMAC_HD_CTL_TAG BIT(1)
	42	/* Add CRC to packets from DMA to PMAC */
	43	#define PMAC_HD_CTL_AC BIT(2)
	44	/* Add status header to packets from PMAC to DMA */
	45	#define PMAC_HD_CTL_AS BIT(3)
	46	/* Remove CRC from packets from PMAC to DMA */
	47	#define PMAC_HD_CTL_RC BIT(4)
	48	/* Remove Layer-2 header from packets from PMAC to DMA */
	49	#define PMAC_HD_CTL_RL2 BIT(5)
	50	/* Status header is present from DMA to PMAC */
	51	#define PMAC_HD_CTL_RXSH BIT(6)
	52	/* Add special tag from PMAC to switch */
	53	#define PMAC_HD_CTL_AST BIT(7)
	54	/* Remove specail Tag from PMAC to DMA */
	55	#define PMAC_HD_CTL_RST BIT(8)
	56	/* Check CRC from DMA to PMAC */
	57	#define PMAC_HD_CTL_CCRC BIT(9)
	58	/* Enable reaction to Pause frames in the PMAC */
	59	#define PMAC_HD_CTL_FC BIT(10)
	60
	61	struct xrx200_chan {
	62	int tx_free;
	63
	64	struct napi_struct napi;
	65	struct ltq_dma_channel dma;
	66
	67	union {
	68	struct sk_buff *skb[LTQ_DESC_NUM];
	69	void *rx_buff[LTQ_DESC_NUM];
	70	};
	71
	72	struct sk_buff *skb_head;
	73	struct sk_buff *skb_tail;
	74
	75	struct xrx200_priv *priv;
	76	};
	77
	78	struct xrx200_priv {
	79	struct clk *clk;
	80
	81	struct xrx200_chan chan_tx;
	82	struct xrx200_chan chan_rx;
	83
	84	u16 rx_buf_size;
	85	u16 rx_skb_size;
	86
	87	struct net_device *net_dev;
	88	struct device *dev;
	89
	90	__iomem void *pmac_reg;
	91	};
	92
	93	static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset)
	94	{
	95	return __raw_readl(priv->pmac_reg + offset);
	96	}
	97
	98	static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset)
	99	{
	100	__raw_writel(val, priv->pmac_reg + offset);
	101	}
	102
	103	static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
	104	u32 offset)
	105	{
	106	u32 val = xrx200_pmac_r32(priv, offset);
	107
	108	val &= ~(clear);
	109	val \|= set;
	110	xrx200_pmac_w32(priv, val, offset);
	111	}
	112
	113	static int xrx200_max_frame_len(int mtu)
	114	{
	115	return VLAN_ETH_HLEN + mtu;
	116	}
	117
	118	static int xrx200_buffer_size(int mtu)
	119	{
	120	return round_up(xrx200_max_frame_len(mtu), 4 * XRX200_DMA_BURST_LEN);
	121	}
	122
	123	static int xrx200_skb_size(u16 buf_size)
	124	{
	125	return SKB_DATA_ALIGN(buf_size + NET_SKB_PAD + NET_IP_ALIGN) +
	126	SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
	127	}
	128
	129	/* drop all the packets from the DMA ring */
	130	static void xrx200_flush_dma(struct xrx200_chan *ch)
	131	{
	132	int i;
	133
	134	for (i = 0; i < LTQ_DESC_NUM; i++) {
	135	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	136
	137	if ((desc->ctl & (LTQ_DMA_OWN \| LTQ_DMA_C)) != LTQ_DMA_C)
	138	break;
	139
	140	desc->ctl = LTQ_DMA_OWN \| LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) \|
	141	ch->priv->rx_buf_size;
	142	ch->dma.desc++;
	143	ch->dma.desc %= LTQ_DESC_NUM;
	144	}
	145	}
	146
	147	static int xrx200_open(struct net_device *net_dev)
	148	{
	149	struct xrx200_priv *priv = netdev_priv(net_dev);
	150
	151	napi_enable(&priv->chan_tx.napi);
	152	ltq_dma_open(&priv->chan_tx.dma);
	153	ltq_dma_enable_irq(&priv->chan_tx.dma);
	154
	155	napi_enable(&priv->chan_rx.napi);
	156	ltq_dma_open(&priv->chan_rx.dma);
	157	/* The boot loader does not always deactivate the receiving of frames
	158	* on the ports and then some packets queue up in the PPE buffers.
	159	* They already passed the PMAC so they do not have the tags
	160	* configured here. Read the these packets here and drop them.
	161	* The HW should have written them into memory after 10us
	162	*/
	163	usleep_range(20, 40);
	164	xrx200_flush_dma(&priv->chan_rx);
	165	ltq_dma_enable_irq(&priv->chan_rx.dma);
	166
	167	netif_wake_queue(net_dev);
	168
	169	return 0;
	170	}
	171
	172	static int xrx200_close(struct net_device *net_dev)
	173	{
	174	struct xrx200_priv *priv = netdev_priv(net_dev);
	175
	176	netif_stop_queue(net_dev);
	177
	178	napi_disable(&priv->chan_rx.napi);
	179	ltq_dma_close(&priv->chan_rx.dma);
	180
	181	napi_disable(&priv->chan_tx.napi);
	182	ltq_dma_close(&priv->chan_tx.dma);
	183
	184	return 0;
	185	}
	186
	187	static int xrx200_alloc_buf(struct xrx200_chan ch, void (*alloc)(unsigned int size))
	188	{
	189	void *buf = ch->rx_buff[ch->dma.desc];
	190	struct xrx200_priv *priv = ch->priv;
	191	dma_addr_t mapping;
	192	int ret = 0;
	193
	194	ch->rx_buff[ch->dma.desc] = alloc(priv->rx_skb_size);
	195	if (!ch->rx_buff[ch->dma.desc]) {
	196	ch->rx_buff[ch->dma.desc] = buf;
	197	ret = -ENOMEM;
	198	goto skip;
	199	}
	200
	201	mapping = dma_map_single(priv->dev, ch->rx_buff[ch->dma.desc],
	202	priv->rx_buf_size, DMA_FROM_DEVICE);
	203	if (unlikely(dma_mapping_error(priv->dev, mapping))) {
	204	skb_free_frag(ch->rx_buff[ch->dma.desc]);
	205	ch->rx_buff[ch->dma.desc] = buf;
	206	ret = -ENOMEM;
	207	goto skip;
	208	}
	209
	210	ch->dma.desc_base[ch->dma.desc].addr = mapping + NET_SKB_PAD + NET_IP_ALIGN;
	211	/* Make sure the address is written before we give it to HW */
	212	wmb();
	213	skip:
	214	ch->dma.desc_base[ch->dma.desc].ctl =
	215	LTQ_DMA_OWN \| LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) \| priv->rx_buf_size;
	216
	217	return ret;
	218	}
	219
	220	static int xrx200_hw_receive(struct xrx200_chan *ch)
	221	{
	222	struct xrx200_priv *priv = ch->priv;
	223	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	224	void *buf = ch->rx_buff[ch->dma.desc];
	225	u32 ctl = desc->ctl;
	226	int len = (ctl & LTQ_DMA_SIZE_MASK);
	227	struct net_device *net_dev = priv->net_dev;
	228	struct sk_buff *skb;
	229	int ret;
	230
	231	ret = xrx200_alloc_buf(ch, napi_alloc_frag);
	232
	233	ch->dma.desc++;
	234	ch->dma.desc %= LTQ_DESC_NUM;
	235
	236	if (ret) {
	237	net_dev->stats.rx_dropped++;
	238	netdev_err(net_dev, "failed to allocate new rx buffer\n");
	239	return ret;
	240	}
	241
	242	skb = build_skb(buf, priv->rx_skb_size);
	243	if (!skb) {
	244	skb_free_frag(buf);
	245	net_dev->stats.rx_dropped++;
	246	return -ENOMEM;
	247	}
	248
	249	skb_reserve(skb, NET_SKB_PAD);
	250	skb_put(skb, len);
	251
	252	/* add buffers to skb via skb->frag_list */
	253	if (ctl & LTQ_DMA_SOP) {
	254	ch->skb_head = skb;
	255	ch->skb_tail = skb;
	256	skb_reserve(skb, NET_IP_ALIGN);
	257	} else if (ch->skb_head) {
	258	if (ch->skb_head == ch->skb_tail)
	259	skb_shinfo(ch->skb_tail)->frag_list = skb;
	260	else
	261	ch->skb_tail->next = skb;
	262	ch->skb_tail = skb;
	263	ch->skb_head->len += skb->len;
	264	ch->skb_head->data_len += skb->len;
	265	ch->skb_head->truesize += skb->truesize;
	266	}
	267
	268	if (ctl & LTQ_DMA_EOP) {
	269	ch->skb_head->protocol = eth_type_trans(ch->skb_head, net_dev);
	270	net_dev->stats.rx_packets++;
	271	net_dev->stats.rx_bytes += ch->skb_head->len;
	272	netif_receive_skb(ch->skb_head);
	273	ch->skb_head = NULL;
	274	ch->skb_tail = NULL;
	275	ret = XRX200_DMA_PACKET_COMPLETE;
	276	} else {
	277	ret = XRX200_DMA_PACKET_IN_PROGRESS;
	278	}
	279
	280	return ret;
	281	}
	282
	283	static int xrx200_poll_rx(struct napi_struct *napi, int budget)
	284	{
	285	struct xrx200_chan *ch = container_of(napi,
	286	struct xrx200_chan, napi);
	287	int rx = 0;
	288	int ret;
	289
	290	while (rx < budget) {
	291	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	292
	293	if ((desc->ctl & (LTQ_DMA_OWN \| LTQ_DMA_C)) == LTQ_DMA_C) {
	294	ret = xrx200_hw_receive(ch);
	295	if (ret == XRX200_DMA_PACKET_IN_PROGRESS)
	296	continue;
	297	if (ret != XRX200_DMA_PACKET_COMPLETE)
	298	break;
	299	rx++;
	300	} else {
	301	break;
	302	}
	303	}
	304
	305	if (rx < budget) {
	306	if (napi_complete_done(&ch->napi, rx))
	307	ltq_dma_enable_irq(&ch->dma);
	308	}
	309
	310	return rx;
	311	}
	312
	313	static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
	314	{
	315	struct xrx200_chan *ch = container_of(napi,
	316	struct xrx200_chan, napi);
	317	struct net_device *net_dev = ch->priv->net_dev;
	318	int pkts = 0;
	319	int bytes = 0;
	320
	321	netif_tx_lock(net_dev);
	322	while (pkts < budget) {
	323	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];
	324
	325	if ((desc->ctl & (LTQ_DMA_OWN \| LTQ_DMA_C)) == LTQ_DMA_C) {
	326	struct sk_buff *skb = ch->skb[ch->tx_free];
	327
	328	pkts++;
	329	bytes += skb->len;
	330	ch->skb[ch->tx_free] = NULL;
	331	consume_skb(skb);
	332	memset(&ch->dma.desc_base[ch->tx_free], 0,
	333	sizeof(struct ltq_dma_desc));
	334	ch->tx_free++;
	335	ch->tx_free %= LTQ_DESC_NUM;
	336	} else {
	337	break;
	338	}
	339	}
	340
	341	net_dev->stats.tx_packets += pkts;
	342	net_dev->stats.tx_bytes += bytes;
	343	netdev_completed_queue(ch->priv->net_dev, pkts, bytes);
	344
	345	netif_tx_unlock(net_dev);
	346	if (netif_queue_stopped(net_dev))
	347	netif_wake_queue(net_dev);
	348
	349	if (pkts < budget) {
	350	if (napi_complete_done(&ch->napi, pkts))
	351	ltq_dma_enable_irq(&ch->dma);
	352	}
	353
	354	return pkts;
	355	}
	356
	357	static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
	358	struct net_device *net_dev)
	359	{
	360	struct xrx200_priv *priv = netdev_priv(net_dev);
	361	struct xrx200_chan *ch = &priv->chan_tx;
	362	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	363	u32 byte_offset;
	364	dma_addr_t mapping;
	365	int len;
	366
	367	skb->dev = net_dev;
	368	if (skb_put_padto(skb, ETH_ZLEN)) {
	369	net_dev->stats.tx_dropped++;
	370	return NETDEV_TX_OK;
	371	}
	372
	373	len = skb->len;
	374
	375	if ((desc->ctl & (LTQ_DMA_OWN \| LTQ_DMA_C)) \|\| ch->skb[ch->dma.desc]) {
	376	netdev_err(net_dev, "tx ring full\n");
	377	netif_stop_queue(net_dev);
	378	return NETDEV_TX_BUSY;
	379	}
	380
	381	ch->skb[ch->dma.desc] = skb;
	382
	383	mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
	384	if (unlikely(dma_mapping_error(priv->dev, mapping)))
	385	goto err_drop;
	386
	387	/* dma needs to start on a burst length value aligned address */
	388	byte_offset = mapping % (XRX200_DMA_BURST_LEN * 4);
	389
	390	desc->addr = mapping - byte_offset;
	391	/* Make sure the address is written before we give it to HW */
	392	wmb();
	393	desc->ctl = LTQ_DMA_OWN \| LTQ_DMA_SOP \| LTQ_DMA_EOP \|
	394	LTQ_DMA_TX_OFFSET(byte_offset) \| (len & LTQ_DMA_SIZE_MASK);
	395	ch->dma.desc++;
	396	ch->dma.desc %= LTQ_DESC_NUM;
	397	if (ch->dma.desc == ch->tx_free)
	398	netif_stop_queue(net_dev);
	399
	400	netdev_sent_queue(net_dev, len);
	401
	402	return NETDEV_TX_OK;
	403
	404	err_drop:
	405	dev_kfree_skb(skb);
	406	net_dev->stats.tx_dropped++;
	407	net_dev->stats.tx_errors++;
	408	return NETDEV_TX_OK;
	409	}
	410
	411	static int
	412	xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
	413	{
	414	struct xrx200_priv *priv = netdev_priv(net_dev);
	415	struct xrx200_chan *ch_rx = &priv->chan_rx;
	416	int old_mtu = net_dev->mtu;
	417	bool running = false;
	418	void *buff;
	419	int curr_desc;
	420	int ret = 0;
	421
	422	WRITE_ONCE(net_dev->mtu, new_mtu);
	423	priv->rx_buf_size = xrx200_buffer_size(new_mtu);
	424	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
	425
	426	if (new_mtu <= old_mtu)
	427	return ret;
	428
	429	running = netif_running(net_dev);
	430	if (running) {
	431	napi_disable(&ch_rx->napi);
	432	ltq_dma_close(&ch_rx->dma);
	433	}
	434
	435	xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
	436	curr_desc = ch_rx->dma.desc;
	437
	438	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
	439	ch_rx->dma.desc++) {
	440	buff = ch_rx->rx_buff[ch_rx->dma.desc];
	441	ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
	442	if (ret) {
	443	WRITE_ONCE(net_dev->mtu, old_mtu);
	444	priv->rx_buf_size = xrx200_buffer_size(old_mtu);
	445	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
	446	break;
	447	}
	448	skb_free_frag(buff);
	449	}
	450
	451	ch_rx->dma.desc = curr_desc;
	452	if (running) {
	453	napi_enable(&ch_rx->napi);
	454	ltq_dma_open(&ch_rx->dma);
	455	ltq_dma_enable_irq(&ch_rx->dma);
	456	}
	457
	458	return ret;
	459	}
	460
	461	static const struct net_device_ops xrx200_netdev_ops = {
	462	.ndo_open = xrx200_open,
	463	.ndo_stop = xrx200_close,
	464	.ndo_start_xmit = xrx200_start_xmit,
	465	.ndo_change_mtu = xrx200_change_mtu,
	466	.ndo_set_mac_address = eth_mac_addr,
	467	.ndo_validate_addr = eth_validate_addr,
	468	};
	469
	470	static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
	471	{
	472	struct xrx200_chan *ch = ptr;
	473
	474	if (napi_schedule_prep(&ch->napi)) {
	475	ltq_dma_disable_irq(&ch->dma);
	476	__napi_schedule(&ch->napi);
	477	}
	478
	479	ltq_dma_ack_irq(&ch->dma);
	480
	481	return IRQ_HANDLED;
	482	}
	483
	484	static int xrx200_dma_init(struct xrx200_priv *priv)
	485	{
	486	struct xrx200_chan *ch_rx = &priv->chan_rx;
	487	struct xrx200_chan *ch_tx = &priv->chan_tx;
	488	int ret = 0;
	489	int i;
	490
	491	ltq_dma_init_port(DMA_PORT_ETOP, XRX200_DMA_BURST_LEN,
	492	XRX200_DMA_BURST_LEN);
	493
	494	ch_rx->dma.nr = XRX200_DMA_RX;
	495	ch_rx->dma.dev = priv->dev;
	496	ch_rx->priv = priv;
	497
	498	ltq_dma_alloc_rx(&ch_rx->dma);
	499	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
	500	ch_rx->dma.desc++) {
	501	ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
	502	if (ret)
	503	goto rx_free;
	504	}
	505	ch_rx->dma.desc = 0;
	506	ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
	507	"xrx200_net_rx", &priv->chan_rx);
	508	if (ret) {
	509	dev_err(priv->dev, "failed to request RX irq %d\n",
	510	ch_rx->dma.irq);
	511	goto rx_ring_free;
	512	}
	513
	514	ch_tx->dma.nr = XRX200_DMA_TX;
	515	ch_tx->dma.dev = priv->dev;
	516	ch_tx->priv = priv;
	517
	518	ltq_dma_alloc_tx(&ch_tx->dma);
	519	ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
	520	"xrx200_net_tx", &priv->chan_tx);
	521	if (ret) {
	522	dev_err(priv->dev, "failed to request TX irq %d\n",
	523	ch_tx->dma.irq);
	524	goto tx_free;
	525	}
	526
	527	return ret;
	528
	529	tx_free:
	530	ltq_dma_free(&ch_tx->dma);
	531
	532	rx_ring_free:
	533	/* free the allocated RX ring */
	534	for (i = 0; i < LTQ_DESC_NUM; i++) {
	535	if (priv->chan_rx.skb[i])
	536	skb_free_frag(priv->chan_rx.rx_buff[i]);
	537	}
	538
	539	rx_free:
	540	ltq_dma_free(&ch_rx->dma);
	541	return ret;
	542	}
	543
	544	static void xrx200_hw_cleanup(struct xrx200_priv *priv)
	545	{
	546	int i;
	547
	548	ltq_dma_free(&priv->chan_tx.dma);
	549	ltq_dma_free(&priv->chan_rx.dma);
	550
	551	/* free the allocated RX ring */
	552	for (i = 0; i < LTQ_DESC_NUM; i++)
	553	skb_free_frag(priv->chan_rx.rx_buff[i]);
	554	}
	555
	556	static int xrx200_probe(struct platform_device *pdev)
	557	{
	558	struct device *dev = &pdev->dev;
	559	struct device_node *np = dev->of_node;
	560	struct xrx200_priv *priv;
	561	struct net_device *net_dev;
	562	int err;
	563
	564	/* alloc the network device */
	565	net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
	566	if (!net_dev)
	567	return -ENOMEM;
	568
	569	priv = netdev_priv(net_dev);
	570	priv->net_dev = net_dev;
	571	priv->dev = dev;
	572
	573	net_dev->netdev_ops = &xrx200_netdev_ops;
	574	SET_NETDEV_DEV(net_dev, dev);
	575	net_dev->min_mtu = ETH_ZLEN;
	576	net_dev->max_mtu = XRX200_DMA_DATA_LEN - xrx200_max_frame_len(0);
	577	priv->rx_buf_size = xrx200_buffer_size(ETH_DATA_LEN);
	578	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
	579
	580	/* load the memory ranges */
	581	priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
	582	if (IS_ERR(priv->pmac_reg))
	583	return PTR_ERR(priv->pmac_reg);
	584
	585	priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
	586	if (priv->chan_rx.dma.irq < 0)
	587	return -ENOENT;
	588	priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
	589	if (priv->chan_tx.dma.irq < 0)
	590	return -ENOENT;
	591
	592	/* get the clock */
	593	priv->clk = devm_clk_get(dev, NULL);
	594	if (IS_ERR(priv->clk)) {
	595	dev_err(dev, "failed to get clock\n");
	596	return PTR_ERR(priv->clk);
	597	}
	598
	599	err = of_get_ethdev_address(np, net_dev);
	600	if (err)
	601	eth_hw_addr_random(net_dev);
	602
	603	/* bring up the dma engine and IP core */
	604	err = xrx200_dma_init(priv);
	605	if (err)
	606	return err;
	607
	608	/* enable clock gate */
	609	err = clk_prepare_enable(priv->clk);
	610	if (err)
	611	goto err_uninit_dma;
	612
	613	/* set IPG to 12 */
	614	xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);
	615
	616	/* enable status header, enable CRC */
	617	xrx200_pmac_mask(priv, 0,
	618	PMAC_HD_CTL_RST \| PMAC_HD_CTL_AST \| PMAC_HD_CTL_RXSH \|
	619	PMAC_HD_CTL_AS \| PMAC_HD_CTL_AC \| PMAC_HD_CTL_RC,
	620	PMAC_HD_CTL);
	621
	622	/* setup NAPI */
	623	netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx);
	624	netif_napi_add_tx(net_dev, &priv->chan_tx.napi,
	625	xrx200_tx_housekeeping);
	626
	627	platform_set_drvdata(pdev, priv);
	628
	629	err = register_netdev(net_dev);
	630	if (err)
	631	goto err_unprepare_clk;
	632
	633	return 0;
	634
	635	err_unprepare_clk:
	636	clk_disable_unprepare(priv->clk);
	637
	638	err_uninit_dma:
	639	xrx200_hw_cleanup(priv);
	640
	641	return err;
	642	}
	643
	644	static void xrx200_remove(struct platform_device *pdev)
	645	{
	646	struct xrx200_priv *priv = platform_get_drvdata(pdev);
	647	struct net_device *net_dev = priv->net_dev;
	648
	649	/* free stack related instances */
	650	netif_stop_queue(net_dev);
	651	netif_napi_del(&priv->chan_tx.napi);
	652	netif_napi_del(&priv->chan_rx.napi);
	653
	654	/* remove the actual device */
	655	unregister_netdev(net_dev);
	656
	657	/* release the clock */
	658	clk_disable_unprepare(priv->clk);
	659
	660	/* shut down hardware */
	661	xrx200_hw_cleanup(priv);
	662	}
	663
	664	static const struct of_device_id xrx200_match[] = {
	665	{ .compatible = "lantiq,xrx200-net" },
	666	{},
	667	};
	668	MODULE_DEVICE_TABLE(of, xrx200_match);
	669
	670	static struct platform_driver xrx200_driver = {
	671	.probe = xrx200_probe,
	672	.remove = xrx200_remove,
	673	.driver = {
	674	.name = "lantiq,xrx200-net",
	675	.of_match_table = xrx200_match,
	676	},
	677	};
	678
	679	module_platform_driver(xrx200_driver);
	680
	681	MODULE_AUTHOR("John Crispin <john@phrozen.org>");
	682	MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
	683	MODULE_LICENSE("GPL");