// SPDX-License-Identifier: GPL-2.0-only
/*
 * Intel IXP4xx Ethernet driver for Linux
 *
 * Copyright (C) 2007 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * Ethernet port config (0x00 is not present on IXP42X):
 *
 * logical port		0x00		0x10		0x20
 * NPE			0 (NPE-A)	1 (NPE-B)	2 (NPE-C)
 * physical PortId	2		0		1
 * TX queue		23		24		25
 * RX-free queue	26		27		28
 * TX-done queue is always 31, per-port RX and TX-ready queues are configurable
 *
 * Queue entries:
 * bits 0 -> 1	- NPE ID (RX and TX-done)
 * bits 0 -> 2	- priority (TX, per 802.1D)
 * bits 3 -> 4	- port ID (user-set?)
 * bits 5 -> 31	- physical descriptor address
 */

#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/net_tstamp.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/ptp_classify.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/soc/ixp4xx/npe.h>
#include <linux/soc/ixp4xx/qmgr.h>
#include <linux/soc/ixp4xx/cpu.h>
#include <linux/types.h>

#define IXP4XX_ETH_NPEA		0x00
#define IXP4XX_ETH_NPEB		0x10
#define IXP4XX_ETH_NPEC		0x20

#include "ixp46x_ts.h"

#define DEBUG_DESC		0
#define DEBUG_RX		0
#define DEBUG_TX		0
#define DEBUG_PKT_BYTES		0
#define DEBUG_MDIO		0
#define DEBUG_CLOSE		0

#define DRV_NAME		"ixp4xx_eth"

#define MAX_NPES		3

#define RX_DESCS		64 /* also length of all RX queues */
#define TX_DESCS		16 /* also length of all TX queues */
#define TXDONE_QUEUE_LEN	64 /* dwords */

#define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
#define REGS_SIZE		0x1000

/* MRU is said to be 14320 in a code dump, the SW manual says that
 * MRU/MTU is 16320 and includes VLAN and ethernet headers.
 * See "IXP400 Software Programmer's Guide" section 10.3.2, page 161.
 *
 * FIXME: we have chosen the safe default (14320) but if you can test
 * jumboframes, experiment with 16320 and see what happens!
 */
#define MAX_MRU			(14320 - VLAN_ETH_HLEN)
#define RX_BUFF_SIZE		ALIGN((NET_IP_ALIGN) + MAX_MRU, 4)

#define NAPI_WEIGHT		16
#define MDIO_INTERVAL		(3 * HZ)
#define MAX_MDIO_RETRIES	100 /* microseconds, typically 30 cycles */
#define MAX_CLOSE_WAIT		1000 /* microseconds, typically 2-3 cycles */

#define NPE_ID(port_id)		((port_id) >> 4)
#define PHYSICAL_ID(port_id)	((NPE_ID(port_id) + 2) % 3)
#define TX_QUEUE(port_id)	(NPE_ID(port_id) + 23)
#define RXFREE_QUEUE(port_id)	(NPE_ID(port_id) + 26)
#define TXDONE_QUEUE		31

#define PTP_SLAVE_MODE		1
#define PTP_MASTER_MODE		2
#define PORT2CHANNEL(p)		NPE_ID(p->id)

/* TX Control Registers */
#define TX_CNTRL0_TX_EN		0x01
#define TX_CNTRL0_HALFDUPLEX	0x02
#define TX_CNTRL0_RETRY		0x04
#define TX_CNTRL0_PAD_EN	0x08
#define TX_CNTRL0_APPEND_FCS	0x10
#define TX_CNTRL0_2DEFER	0x20
#define TX_CNTRL0_RMII		0x40 /* reduced MII */
#define TX_CNTRL1_RETRIES	0x0F /* 4 bits */

/* RX Control Registers */
#define RX_CNTRL0_RX_EN		0x01
#define RX_CNTRL0_PADSTRIP_EN	0x02
#define RX_CNTRL0_SEND_FCS	0x04
#define RX_CNTRL0_PAUSE_EN	0x08
#define RX_CNTRL0_LOOP_EN	0x10
#define RX_CNTRL0_ADDR_FLTR_EN	0x20
#define RX_CNTRL0_RX_RUNT_EN	0x40
#define RX_CNTRL0_BCAST_DIS	0x80
#define RX_CNTRL1_DEFER_EN	0x01

/* Core Control Register */
#define CORE_RESET		0x01
#define CORE_RX_FIFO_FLUSH	0x02
#define CORE_TX_FIFO_FLUSH	0x04
#define CORE_SEND_JAM		0x08
#define CORE_MDC_EN		0x10 /* MDIO using NPE-B ETH-0 only */

#define DEFAULT_TX_CNTRL0	(TX_CNTRL0_TX_EN | TX_CNTRL0_RETRY |	\
				 TX_CNTRL0_PAD_EN | TX_CNTRL0_APPEND_FCS | \
				 TX_CNTRL0_2DEFER)
#define DEFAULT_RX_CNTRL0	RX_CNTRL0_RX_EN
#define DEFAULT_CORE_CNTRL	CORE_MDC_EN


/* NPE message codes */
#define NPE_GETSTATUS			0x00
#define NPE_EDB_SETPORTADDRESS		0x01
#define NPE_EDB_GETMACADDRESSDATABASE	0x02
#define NPE_EDB_SETMACADDRESSSDATABASE	0x03
#define NPE_GETSTATS			0x04
#define NPE_RESETSTATS			0x05
#define NPE_SETMAXFRAMELENGTHS		0x06
#define NPE_VLAN_SETRXTAGMODE		0x07
#define NPE_VLAN_SETDEFAULTRXVID	0x08
#define NPE_VLAN_SETPORTVLANTABLEENTRY	0x09
#define NPE_VLAN_SETPORTVLANTABLERANGE	0x0A
#define NPE_VLAN_SETRXQOSENTRY		0x0B
#define NPE_VLAN_SETPORTIDEXTRACTIONMODE 0x0C
#define NPE_STP_SETBLOCKINGSTATE	0x0D
#define NPE_FW_SETFIREWALLMODE		0x0E
#define NPE_PC_SETFRAMECONTROLDURATIONID 0x0F
#define NPE_PC_SETAPMACTABLE		0x11
#define NPE_SETLOOPBACK_MODE		0x12
#define NPE_PC_SETBSSIDTABLE		0x13
#define NPE_ADDRESS_FILTER_CONFIG	0x14
#define NPE_APPENDFCSCONFIG		0x15
#define NPE_NOTIFY_MAC_RECOVERY_DONE	0x16
#define NPE_MAC_RECOVERY_START		0x17


#ifdef __ARMEB__
typedef struct sk_buff buffer_t;
#define free_buffer dev_kfree_skb
#define free_buffer_irq dev_consume_skb_irq
#else
typedef void buffer_t;
#define free_buffer kfree
#define free_buffer_irq kfree
#endif

/* Information about built-in Ethernet MAC interfaces */
struct eth_plat_info {
	u8 rxq;		/* configurable, currently 0 - 31 only */
	u8 txreadyq;
	u8 hwaddr[ETH_ALEN];
	u8 npe;		/* NPE instance used by this interface */
	bool has_mdio;	/* If this instance has an MDIO bus */
};

struct eth_regs {
	u32 tx_control[2], __res1[2];		/* 000 */
	u32 rx_control[2], __res2[2];		/* 010 */
	u32 random_seed, __res3[3];		/* 020 */
	u32 partial_empty_threshold, __res4;	/* 030 */
	u32 partial_full_threshold, __res5;	/* 038 */
	u32 tx_start_bytes, __res6[3];		/* 040 */
	u32 tx_deferral, rx_deferral, __res7[2];/* 050 */
	u32 tx_2part_deferral[2], __res8[2];	/* 060 */
	u32 slot_time, __res9[3];		/* 070 */
	u32 mdio_command[4];			/* 080 */
	u32 mdio_status[4];			/* 090 */
	u32 mcast_mask[6], __res10[2];		/* 0A0 */
	u32 mcast_addr[6], __res11[2];		/* 0C0 */
	u32 int_clock_threshold, __res12[3];	/* 0E0 */
	u32 hw_addr[6], __res13[61];		/* 0F0 */
	u32 core_control;			/* 1FC */
};

struct port {
	struct eth_regs __iomem *regs;
	struct ixp46x_ts_regs __iomem *timesync_regs;
	int phc_index;
	struct npe *npe;
	struct net_device *netdev;
	struct napi_struct napi;
	struct eth_plat_info *plat;
	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
	struct desc *desc_tab;	/* coherent */
	dma_addr_t desc_tab_phys;
	int id;			/* logical port ID */
	int speed, duplex;
	u8 firmware[4];
	int hwts_tx_en;
	int hwts_rx_en;
};

/* NPE message structure */
struct msg {
#ifdef __ARMEB__
	u8 cmd, eth_id, byte2, byte3;
	u8 byte4, byte5, byte6, byte7;
#else
	u8 byte3, byte2, eth_id, cmd;
	u8 byte7, byte6, byte5, byte4;
#endif
};

/* Ethernet packet descriptor */
struct desc {
	u32 next;		/* pointer to next buffer, unused */

#ifdef __ARMEB__
	u16 buf_len;		/* buffer length */
	u16 pkt_len;		/* packet length */
	u32 data;		/* pointer to data buffer in RAM */
	u8 dest_id;
	u8 src_id;
	u16 flags;
	u8 qos;
	u8 padlen;
	u16 vlan_tci;
#else
	u16 pkt_len;		/* packet length */
	u16 buf_len;		/* buffer length */
	u32 data;		/* pointer to data buffer in RAM */
	u16 flags;
	u8 src_id;
	u8 dest_id;
	u16 vlan_tci;
	u8 padlen;
	u8 qos;
#endif

#ifdef __ARMEB__
	u8 dst_mac_0, dst_mac_1, dst_mac_2, dst_mac_3;
	u8 dst_mac_4, dst_mac_5, src_mac_0, src_mac_1;
	u8 src_mac_2, src_mac_3, src_mac_4, src_mac_5;
#else
	u8 dst_mac_3, dst_mac_2, dst_mac_1, dst_mac_0;
	u8 src_mac_1, src_mac_0, dst_mac_5, dst_mac_4;
	u8 src_mac_5, src_mac_4, src_mac_3, src_mac_2;
#endif
};


#define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
				 (n) * sizeof(struct desc))
#define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])

#define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
				 ((n) + RX_DESCS) * sizeof(struct desc))
#define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])

#ifndef __ARMEB__
static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
{
	int i;
	for (i = 0; i < cnt; i++)
		dest[i] = swab32(src[i]);
}
#endif

static DEFINE_SPINLOCK(mdio_lock);
static struct eth_regs __iomem *mdio_regs; /* mdio command and status only */
static struct mii_bus *mdio_bus;
static struct device_node *mdio_bus_np;
static int ports_open;
static struct port *npe_port_tab[MAX_NPES];
static struct dma_pool *dma_pool;

static int ixp_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seqid)
{
	u8 *data = skb->data;
	unsigned int offset;
	u16 *hi, *id;
	u32 lo;

	if (ptp_classify_raw(skb) != PTP_CLASS_V1_IPV4)
		return 0;

	offset = ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN;

	if (skb->len < offset + OFF_PTP_SEQUENCE_ID + sizeof(seqid))
		return 0;

	hi = (u16 *)(data + offset + OFF_PTP_SOURCE_UUID);
	id = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);

	memcpy(&lo, &hi[1], sizeof(lo));

	return (uid_hi == ntohs(*hi) &&
		uid_lo == ntohl(lo) &&
		seqid  == ntohs(*id));
}

static void ixp_rx_timestamp(struct port *port, struct sk_buff *skb)
{
	struct skb_shared_hwtstamps *shhwtstamps;
	struct ixp46x_ts_regs *regs;
	u64 ns;
	u32 ch, hi, lo, val;
	u16 uid, seq;

	if (!port->hwts_rx_en)
		return;

	ch = PORT2CHANNEL(port);

	regs = port->timesync_regs;

	val = __raw_readl(&regs->channel[ch].ch_event);

	if (!(val & RX_SNAPSHOT_LOCKED))
		return;

	lo = __raw_readl(&regs->channel[ch].src_uuid_lo);
	hi = __raw_readl(&regs->channel[ch].src_uuid_hi);

	uid = hi & 0xffff;
	seq = (hi >> 16) & 0xffff;

	if (!ixp_ptp_match(skb, htons(uid), htonl(lo), htons(seq)))
		goto out;

	lo = __raw_readl(&regs->channel[ch].rx_snap_lo);
	hi = __raw_readl(&regs->channel[ch].rx_snap_hi);
	ns = ((u64) hi) << 32;
	ns |= lo;
	ns <<= TICKS_NS_SHIFT;

	shhwtstamps = skb_hwtstamps(skb);
	memset(shhwtstamps, 0, sizeof(*shhwtstamps));
	shhwtstamps->hwtstamp = ns_to_ktime(ns);
out:
	__raw_writel(RX_SNAPSHOT_LOCKED, &regs->channel[ch].ch_event);
}

static void ixp_tx_timestamp(struct port *port, struct sk_buff *skb)
{
	struct skb_shared_hwtstamps shhwtstamps;
	struct ixp46x_ts_regs *regs;
	struct skb_shared_info *shtx;
	u64 ns;
	u32 ch, cnt, hi, lo, val;

	shtx = skb_shinfo(skb);
	if (unlikely(shtx->tx_flags & SKBTX_HW_TSTAMP && port->hwts_tx_en))
		shtx->tx_flags |= SKBTX_IN_PROGRESS;
	else
		return;

	ch = PORT2CHANNEL(port);

	regs = port->timesync_regs;

	/*
	 * This really stinks, but we have to poll for the Tx time stamp.
	 * Usually, the time stamp is ready after 4 to 6 microseconds.
	 */
	for (cnt = 0; cnt < 100; cnt++) {
		val = __raw_readl(&regs->channel[ch].ch_event);
		if (val & TX_SNAPSHOT_LOCKED)
			break;
		udelay(1);
	}
	if (!(val & TX_SNAPSHOT_LOCKED)) {
		shtx->tx_flags &= ~SKBTX_IN_PROGRESS;
		return;
	}

	lo = __raw_readl(&regs->channel[ch].tx_snap_lo);
	hi = __raw_readl(&regs->channel[ch].tx_snap_hi);
	ns = ((u64) hi) << 32;
	ns |= lo;
	ns <<= TICKS_NS_SHIFT;

	memset(&shhwtstamps, 0, sizeof(shhwtstamps));
	shhwtstamps.hwtstamp = ns_to_ktime(ns);
	skb_tstamp_tx(skb, &shhwtstamps);

	__raw_writel(TX_SNAPSHOT_LOCKED, &regs->channel[ch].ch_event);
}

static int hwtstamp_set(struct net_device *netdev, struct ifreq *ifr)
{
	struct hwtstamp_config cfg;
	struct ixp46x_ts_regs *regs;
	struct port *port = netdev_priv(netdev);
	int ret;
	int ch;

	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
		return -EFAULT;

	ret = ixp46x_ptp_find(&port->timesync_regs, &port->phc_index);
	if (ret)
		return ret;

	ch = PORT2CHANNEL(port);
	regs = port->timesync_regs;

	if (cfg.tx_type != HWTSTAMP_TX_OFF && cfg.tx_type != HWTSTAMP_TX_ON)
		return -ERANGE;

	switch (cfg.rx_filter) {
	case HWTSTAMP_FILTER_NONE:
		port->hwts_rx_en = 0;
		break;
	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
		port->hwts_rx_en = PTP_SLAVE_MODE;
		__raw_writel(0, &regs->channel[ch].ch_control);
		break;
	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
		port->hwts_rx_en = PTP_MASTER_MODE;
		__raw_writel(MASTER_MODE, &regs->channel[ch].ch_control);
		break;
	default:
		return -ERANGE;
	}

	port->hwts_tx_en = cfg.tx_type == HWTSTAMP_TX_ON;

	/* Clear out any old time stamps. */
	__raw_writel(TX_SNAPSHOT_LOCKED | RX_SNAPSHOT_LOCKED,
		     &regs->channel[ch].ch_event);

	return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
}

static int hwtstamp_get(struct net_device *netdev, struct ifreq *ifr)
{
	struct hwtstamp_config cfg;
	struct port *port = netdev_priv(netdev);

	cfg.flags = 0;
	cfg.tx_type = port->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;

	switch (port->hwts_rx_en) {
	case 0:
		cfg.rx_filter = HWTSTAMP_FILTER_NONE;
		break;
	case PTP_SLAVE_MODE:
		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_SYNC;
		break;
	case PTP_MASTER_MODE:
		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ;
		break;
	default:
		WARN_ON_ONCE(1);
		return -ERANGE;
	}

	return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
}

static int ixp4xx_mdio_cmd(struct mii_bus *bus, int phy_id, int location,
			   int write, u16 cmd)
{
	int cycles = 0;

	if (__raw_readl(&mdio_regs->mdio_command[3]) & 0x80) {
		printk(KERN_ERR "%s: MII not ready to transmit\n", bus->name);
		return -1;
	}

	if (write) {
		__raw_writel(cmd & 0xFF, &mdio_regs->mdio_command[0]);
		__raw_writel(cmd >> 8, &mdio_regs->mdio_command[1]);
	}
	__raw_writel(((phy_id << 5) | location) & 0xFF,
		     &mdio_regs->mdio_command[2]);
	__raw_writel((phy_id >> 3) | (write << 2) | 0x80 /* GO */,
		     &mdio_regs->mdio_command[3]);

	while ((cycles < MAX_MDIO_RETRIES) &&
	       (__raw_readl(&mdio_regs->mdio_command[3]) & 0x80)) {
		udelay(1);
		cycles++;
	}

	if (cycles == MAX_MDIO_RETRIES) {
		printk(KERN_ERR "%s #%i: MII write failed\n", bus->name,
		       phy_id);
		return -1;
	}

#if DEBUG_MDIO
	printk(KERN_DEBUG "%s #%i: mdio_%s() took %i cycles\n", bus->name,
	       phy_id, write ? "write" : "read", cycles);
#endif

	if (write)
		return 0;

	if (__raw_readl(&mdio_regs->mdio_status[3]) & 0x80) {
#if DEBUG_MDIO
		printk(KERN_DEBUG "%s #%i: MII read failed\n", bus->name,
		       phy_id);
#endif
		return 0xFFFF; /* don't return error */
	}

	return (__raw_readl(&mdio_regs->mdio_status[0]) & 0xFF) |
		((__raw_readl(&mdio_regs->mdio_status[1]) & 0xFF) << 8);
}

static int ixp4xx_mdio_read(struct mii_bus *bus, int phy_id, int location)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&mdio_lock, flags);
	ret = ixp4xx_mdio_cmd(bus, phy_id, location, 0, 0);
	spin_unlock_irqrestore(&mdio_lock, flags);
#if DEBUG_MDIO
	printk(KERN_DEBUG "%s #%i: MII read [%i] -> 0x%X\n", bus->name,
	       phy_id, location, ret);
#endif
	return ret;
}

static int ixp4xx_mdio_write(struct mii_bus *bus, int phy_id, int location,
			     u16 val)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&mdio_lock, flags);
	ret = ixp4xx_mdio_cmd(bus, phy_id, location, 1, val);
	spin_unlock_irqrestore(&mdio_lock, flags);
#if DEBUG_MDIO
	printk(KERN_DEBUG "%s #%i: MII write [%i] <- 0x%X, err = %i\n",
	       bus->name, phy_id, location, val, ret);
#endif
	return ret;
}

static int ixp4xx_mdio_register(struct eth_regs __iomem *regs)
{
	int err;

	if (!(mdio_bus = mdiobus_alloc()))
		return -ENOMEM;

	mdio_regs = regs;
	__raw_writel(DEFAULT_CORE_CNTRL, &mdio_regs->core_control);
	mdio_bus->name = "IXP4xx MII Bus";
	mdio_bus->read = &ixp4xx_mdio_read;
	mdio_bus->write = &ixp4xx_mdio_write;
	snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "ixp4xx-eth-0");

	err = of_mdiobus_register(mdio_bus, mdio_bus_np);
	if (err)
		mdiobus_free(mdio_bus);
	return err;
}

static void ixp4xx_mdio_remove(void)
{
	mdiobus_unregister(mdio_bus);
	mdiobus_free(mdio_bus);
}


static void ixp4xx_adjust_link(struct net_device *dev)
{
	struct port *port = netdev_priv(dev);
	struct phy_device *phydev = dev->phydev;

	if (!phydev->link) {
		if (port->speed) {
			port->speed = 0;
			printk(KERN_INFO "%s: link down\n", dev->name);
		}
		return;
	}

	if (port->speed == phydev->speed && port->duplex == phydev->duplex)
		return;

	port->speed = phydev->speed;
	port->duplex = phydev->duplex;

	if (port->duplex)
		__raw_writel(DEFAULT_TX_CNTRL0 & ~TX_CNTRL0_HALFDUPLEX,
			     &port->regs->tx_control[0]);
	else
		__raw_writel(DEFAULT_TX_CNTRL0 | TX_CNTRL0_HALFDUPLEX,
			     &port->regs->tx_control[0]);

	netdev_info(dev, "%s: link up, speed %u Mb/s, %s duplex\n",
		    dev->name, port->speed, port->duplex ? "full" : "half");
}


static inline void debug_pkt(struct net_device *dev, const char *func,
			     u8 *data, int len)
{
#if DEBUG_PKT_BYTES
	int i;

	netdev_debug(dev, "%s(%i) ", func, len);
	for (i = 0; i < len; i++) {
		if (i >= DEBUG_PKT_BYTES)
			break;
		printk("%s%02X",
		       ((i == 6) || (i == 12) || (i >= 14)) ? " " : "",
		       data[i]);
	}
	printk("\n");
#endif
}


static inline void debug_desc(u32 phys, struct desc *desc)
{
#if DEBUG_DESC
	printk(KERN_DEBUG "%X: %X %3X %3X %08X %2X < %2X %4X %X"
	       " %X %X %02X%02X%02X%02X%02X%02X < %02X%02X%02X%02X%02X%02X\n",
	       phys, desc->next, desc->buf_len, desc->pkt_len,
	       desc->data, desc->dest_id, desc->src_id, desc->flags,
	       desc->qos, desc->padlen, desc->vlan_tci,
	       desc->dst_mac_0, desc->dst_mac_1, desc->dst_mac_2,
	       desc->dst_mac_3, desc->dst_mac_4, desc->dst_mac_5,
	       desc->src_mac_0, desc->src_mac_1, desc->src_mac_2,
	       desc->src_mac_3, desc->src_mac_4, desc->src_mac_5);
#endif
}

static inline int queue_get_desc(unsigned int queue, struct port *port,
				 int is_tx)
{
	u32 phys, tab_phys, n_desc;
	struct desc *tab;

	if (!(phys = qmgr_get_entry(queue)))
		return -1;

	phys &= ~0x1F; /* mask out non-address bits */
	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
	n_desc = (phys - tab_phys) / sizeof(struct desc);
	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
	debug_desc(phys, &tab[n_desc]);
	BUG_ON(tab[n_desc].next);
	return n_desc;
}

static inline void queue_put_desc(unsigned int queue, u32 phys,
				  struct desc *desc)
{
	debug_desc(phys, desc);
	BUG_ON(phys & 0x1F);
	qmgr_put_entry(queue, phys);
	/* Don't check for queue overflow here, we've allocated sufficient
	   length and queues >= 32 don't support this check anyway. */
}


static inline void dma_unmap_tx(struct port *port, struct desc *desc)
{
#ifdef __ARMEB__
	dma_unmap_single(&port->netdev->dev, desc->data,
			 desc->buf_len, DMA_TO_DEVICE);
#else
	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
			 ALIGN((desc->data & 3) + desc->buf_len, 4),
			 DMA_TO_DEVICE);
#endif
}


static void eth_rx_irq(void *pdev)
{
	struct net_device *dev = pdev;
	struct port *port = netdev_priv(dev);

#if DEBUG_RX
	printk(KERN_DEBUG "%s: eth_rx_irq\n", dev->name);
#endif
	qmgr_disable_irq(port->plat->rxq);
	napi_schedule(&port->napi);
}

static int eth_poll(struct napi_struct *napi, int budget)
{
	struct port *port = container_of(napi, struct port, napi);
	struct net_device *dev = port->netdev;
	unsigned int rxq = port->plat->rxq, rxfreeq = RXFREE_QUEUE(port->id);
	int received = 0;

#if DEBUG_RX
	netdev_debug(dev, "eth_poll\n");
#endif

	while (received < budget) {
		struct sk_buff *skb;
		struct desc *desc;
		int n;
#ifdef __ARMEB__
		struct sk_buff *temp;
		u32 phys;
#endif

		if ((n = queue_get_desc(rxq, port, 0)) < 0) {
#if DEBUG_RX
			netdev_debug(dev, "eth_poll napi_complete\n");
#endif
			napi_complete(napi);
			qmgr_enable_irq(rxq);
			if (!qmgr_stat_below_low_watermark(rxq) &&
			    napi_schedule(napi)) { /* not empty again */
#if DEBUG_RX
				netdev_debug(dev, "eth_poll napi_schedule succeeded\n");
#endif
				qmgr_disable_irq(rxq);
				continue;
			}
#if DEBUG_RX
			netdev_debug(dev, "eth_poll all done\n");
#endif
			return received; /* all work done */
		}

		desc = rx_desc_ptr(port, n);

#ifdef __ARMEB__
		if ((skb = netdev_alloc_skb(dev, RX_BUFF_SIZE))) {
			phys = dma_map_single(&dev->dev, skb->data,
					      RX_BUFF_SIZE, DMA_FROM_DEVICE);
			if (dma_mapping_error(&dev->dev, phys)) {
				dev_kfree_skb(skb);
				skb = NULL;
			}
		}
#else
		skb = netdev_alloc_skb(dev,
				       ALIGN(NET_IP_ALIGN + desc->pkt_len, 4));
#endif

		if (!skb) {
			dev->stats.rx_dropped++;
			/* put the desc back on RX-ready queue */
			desc->buf_len = MAX_MRU;
			desc->pkt_len = 0;
			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
			continue;
		}

		/* process received frame */
#ifdef __ARMEB__
		temp = skb;
		skb = port->rx_buff_tab[n];
		dma_unmap_single(&dev->dev, desc->data - NET_IP_ALIGN,
				 RX_BUFF_SIZE, DMA_FROM_DEVICE);
#else
		dma_sync_single_for_cpu(&dev->dev, desc->data - NET_IP_ALIGN,
					RX_BUFF_SIZE, DMA_FROM_DEVICE);
		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
			      ALIGN(NET_IP_ALIGN + desc->pkt_len, 4) / 4);
#endif
		skb_reserve(skb, NET_IP_ALIGN);
		skb_put(skb, desc->pkt_len);

		debug_pkt(dev, "eth_poll", skb->data, skb->len);

		ixp_rx_timestamp(port, skb);
		skb->protocol = eth_type_trans(skb, dev);
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += skb->len;
		netif_receive_skb(skb);

		/* put the new buffer on RX-free queue */
#ifdef __ARMEB__
		port->rx_buff_tab[n] = temp;
		desc->data = phys + NET_IP_ALIGN;
#endif
		desc->buf_len = MAX_MRU;
		desc->pkt_len = 0;
		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
		received++;
	}

#if DEBUG_RX
	netdev_debug(dev, "eth_poll(): end, not all work done\n");
#endif
	return received;		/* not all work done */
}


static void eth_txdone_irq(void *unused)
{
	u32 phys;

#if DEBUG_TX
	printk(KERN_DEBUG DRV_NAME ": eth_txdone_irq\n");
#endif
	while ((phys = qmgr_get_entry(TXDONE_QUEUE)) != 0) {
		u32 npe_id, n_desc;
		struct port *port;
		struct desc *desc;
		int start;

		npe_id = phys & 3;
		BUG_ON(npe_id >= MAX_NPES);
		port = npe_port_tab[npe_id];
		BUG_ON(!port);
		phys &= ~0x1F; /* mask out non-address bits */
		n_desc = (phys - tx_desc_phys(port, 0)) / sizeof(struct desc);
		BUG_ON(n_desc >= TX_DESCS);
		desc = tx_desc_ptr(port, n_desc);
		debug_desc(phys, desc);

		if (port->tx_buff_tab[n_desc]) { /* not the draining packet */
			port->netdev->stats.tx_packets++;
			port->netdev->stats.tx_bytes += desc->pkt_len;

			dma_unmap_tx(port, desc);
#if DEBUG_TX
			printk(KERN_DEBUG "%s: eth_txdone_irq free %p\n",
			       port->netdev->name, port->tx_buff_tab[n_desc]);
#endif
			free_buffer_irq(port->tx_buff_tab[n_desc]);
			port->tx_buff_tab[n_desc] = NULL;
		}

		start = qmgr_stat_below_low_watermark(port->plat->txreadyq);
		queue_put_desc(port->plat->txreadyq, phys, desc);
		if (start) { /* TX-ready queue was empty */
#if DEBUG_TX
			printk(KERN_DEBUG "%s: eth_txdone_irq xmit ready\n",
			       port->netdev->name);
#endif
			netif_wake_queue(port->netdev);
		}
	}
}

static netdev_tx_t eth_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct port *port = netdev_priv(dev);
	unsigned int txreadyq = port->plat->txreadyq;
	int len, offset, bytes, n;
	void *mem;
	u32 phys;
	struct desc *desc;

#if DEBUG_TX
	netdev_debug(dev, "eth_xmit\n");
#endif

	if (unlikely(skb->len > MAX_MRU)) {
		dev_kfree_skb(skb);
		dev->stats.tx_errors++;
		return NETDEV_TX_OK;
	}

	debug_pkt(dev, "eth_xmit", skb->data, skb->len);

	len = skb->len;
#ifdef __ARMEB__
	offset = 0; /* no need to keep alignment */
	bytes = len;
	mem = skb->data;
#else
	offset = (uintptr_t)skb->data & 3; /* keep 32-bit alignment */
	bytes = ALIGN(offset + len, 4);
	if (!(mem = kmalloc(bytes, GFP_ATOMIC))) {
		dev_kfree_skb(skb);
		dev->stats.tx_dropped++;
		return NETDEV_TX_OK;
	}
	memcpy_swab32(mem, (u32 *)((uintptr_t)skb->data & ~3), bytes / 4);
#endif

	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
	if (dma_mapping_error(&dev->dev, phys)) {
		dev_kfree_skb(skb);
#ifndef __ARMEB__
		kfree(mem);
#endif
		dev->stats.tx_dropped++;
		return NETDEV_TX_OK;
	}

	n = queue_get_desc(txreadyq, port, 1);
	BUG_ON(n < 0);
	desc = tx_desc_ptr(port, n);

#ifdef __ARMEB__
	port->tx_buff_tab[n] = skb;
#else
	port->tx_buff_tab[n] = mem;
#endif
	desc->data = phys + offset;
	desc->buf_len = desc->pkt_len = len;

	/* NPE firmware pads short frames with zeros internally */
	wmb();
	queue_put_desc(TX_QUEUE(port->id), tx_desc_phys(port, n), desc);

	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
#if DEBUG_TX
		netdev_debug(dev, "eth_xmit queue full\n");
#endif
		netif_stop_queue(dev);
		/* we could miss TX ready interrupt */
		/* really empty in fact */
		if (!qmgr_stat_below_low_watermark(txreadyq)) {
#if DEBUG_TX
			netdev_debug(dev, "eth_xmit ready again\n");
#endif
			netif_wake_queue(dev);
		}
	}

#if DEBUG_TX
	netdev_debug(dev, "eth_xmit end\n");
#endif

	ixp_tx_timestamp(port, skb);
	skb_tx_timestamp(skb);

#ifndef __ARMEB__
	dev_kfree_skb(skb);
#endif
	return NETDEV_TX_OK;
}


static void eth_set_mcast_list(struct net_device *dev)
{
	struct port *port = netdev_priv(dev);
	struct netdev_hw_addr *ha;
	u8 diffs[ETH_ALEN], *addr;
	int i;
	static const u8 allmulti[] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00 };

	if ((dev->flags & IFF_ALLMULTI) && !(dev->flags & IFF_PROMISC)) {
		for (i = 0; i < ETH_ALEN; i++) {
			__raw_writel(allmulti[i], &port->regs->mcast_addr[i]);
			__raw_writel(allmulti[i], &port->regs->mcast_mask[i]);
		}
		__raw_writel(DEFAULT_RX_CNTRL0 | RX_CNTRL0_ADDR_FLTR_EN,
			&port->regs->rx_control[0]);
		return;
	}

	if ((dev->flags & IFF_PROMISC) || netdev_mc_empty(dev)) {
		__raw_writel(DEFAULT_RX_CNTRL0 & ~RX_CNTRL0_ADDR_FLTR_EN,
			     &port->regs->rx_control[0]);
		return;
	}

	eth_zero_addr(diffs);

	addr = NULL;
	netdev_for_each_mc_addr(ha, dev) {
		if (!addr)
			addr = ha->addr; /* first MAC address */
		for (i = 0; i < ETH_ALEN; i++)
			diffs[i] |= addr[i] ^ ha->addr[i];
	}

	for (i = 0; i < ETH_ALEN; i++) {
		__raw_writel(addr[i], &port->regs->mcast_addr[i]);
		__raw_writel(~diffs[i], &port->regs->mcast_mask[i]);
	}

	__raw_writel(DEFAULT_RX_CNTRL0 | RX_CNTRL0_ADDR_FLTR_EN,
		     &port->regs->rx_control[0]);
}


static int eth_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
{
	if (!netif_running(dev))
		return -EINVAL;

	if (cpu_is_ixp46x()) {
		if (cmd == SIOCSHWTSTAMP)
			return hwtstamp_set(dev, req);
		if (cmd == SIOCGHWTSTAMP)
			return hwtstamp_get(dev, req);
	}

	return phy_mii_ioctl(dev->phydev, req, cmd);
}

/* ethtool support */

static void ixp4xx_get_drvinfo(struct net_device *dev,
			       struct ethtool_drvinfo *info)
{
	struct port *port = netdev_priv(dev);

	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
	snprintf(info->fw_version, sizeof(info->fw_version), "%u:%u:%u:%u",
		 port->firmware[0], port->firmware[1],
		 port->firmware[2], port->firmware[3]);
	strscpy(info->bus_info, "internal", sizeof(info->bus_info));
}

static int ixp4xx_get_ts_info(struct net_device *dev,
			      struct kernel_ethtool_ts_info *info)
{
	struct port *port = netdev_priv(dev);

	if (port->phc_index < 0)
		ixp46x_ptp_find(&port->timesync_regs, &port->phc_index);

	info->phc_index = port->phc_index;

	if (info->phc_index < 0) {
		info->so_timestamping =
			SOF_TIMESTAMPING_TX_SOFTWARE;
		return 0;
	}
	info->so_timestamping =
		SOF_TIMESTAMPING_TX_HARDWARE |
		SOF_TIMESTAMPING_RX_HARDWARE |
		SOF_TIMESTAMPING_RAW_HARDWARE;
	info->tx_types =
		(1 << HWTSTAMP_TX_OFF) |
		(1 << HWTSTAMP_TX_ON);
	info->rx_filters =
		(1 << HWTSTAMP_FILTER_NONE) |
		(1 << HWTSTAMP_FILTER_PTP_V1_L4_SYNC) |
		(1 << HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ);
	return 0;
}

static const struct ethtool_ops ixp4xx_ethtool_ops = {
	.get_drvinfo = ixp4xx_get_drvinfo,
	.nway_reset = phy_ethtool_nway_reset,
	.get_link = ethtool_op_get_link,
	.get_ts_info = ixp4xx_get_ts_info,
	.get_link_ksettings = phy_ethtool_get_link_ksettings,
	.set_link_ksettings = phy_ethtool_set_link_ksettings,
};


static int request_queues(struct port *port)
{
	int err;

	err = qmgr_request_queue(RXFREE_QUEUE(port->id), RX_DESCS, 0, 0,
				 "%s:RX-free", port->netdev->name);
	if (err)
		return err;

	err = qmgr_request_queue(port->plat->rxq, RX_DESCS, 0, 0,
				 "%s:RX", port->netdev->name);
	if (err)
		goto rel_rxfree;

	err = qmgr_request_queue(TX_QUEUE(port->id), TX_DESCS, 0, 0,
				 "%s:TX", port->netdev->name);
	if (err)
		goto rel_rx;

	err = qmgr_request_queue(port->plat->txreadyq, TX_DESCS, 0, 0,
				 "%s:TX-ready", port->netdev->name);
	if (err)
		goto rel_tx;

	/* TX-done queue handles skbs sent out by the NPEs */
	if (!ports_open) {
		err = qmgr_request_queue(TXDONE_QUEUE, TXDONE_QUEUE_LEN, 0, 0,
					 "%s:TX-done", DRV_NAME);
		if (err)
			goto rel_txready;
	}
	return 0;

rel_txready:
	qmgr_release_queue(port->plat->txreadyq);
rel_tx:
	qmgr_release_queue(TX_QUEUE(port->id));
rel_rx:
	qmgr_release_queue(port->plat->rxq);
rel_rxfree:
	qmgr_release_queue(RXFREE_QUEUE(port->id));
	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
	       port->netdev->name);
	return err;
}

static void release_queues(struct port *port)
{
	qmgr_release_queue(RXFREE_QUEUE(port->id));
	qmgr_release_queue(port->plat->rxq);
	qmgr_release_queue(TX_QUEUE(port->id));
	qmgr_release_queue(port->plat->txreadyq);

	if (!ports_open)
		qmgr_release_queue(TXDONE_QUEUE);
}

static int init_queues(struct port *port)
{
	int i;

	if (!ports_open) {
		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
					   POOL_ALLOC_SIZE, 32, 0);
		if (!dma_pool)
			return -ENOMEM;
	}

	port->desc_tab = dma_pool_zalloc(dma_pool, GFP_KERNEL, &port->desc_tab_phys);
	if (!port->desc_tab)
		return -ENOMEM;
	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));

	/* Setup RX buffers */
	for (i = 0; i < RX_DESCS; i++) {
		struct desc *desc = rx_desc_ptr(port, i);
		buffer_t *buff; /* skb or kmalloc()ated memory */
		void *data;
#ifdef __ARMEB__
		if (!(buff = netdev_alloc_skb(port->netdev, RX_BUFF_SIZE)))
			return -ENOMEM;
		data = buff->data;
#else
		if (!(buff = kmalloc(RX_BUFF_SIZE, GFP_KERNEL)))
			return -ENOMEM;
		data = buff;
#endif
		desc->buf_len = MAX_MRU;
		desc->data = dma_map_single(&port->netdev->dev, data,
					    RX_BUFF_SIZE, DMA_FROM_DEVICE);
		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
			free_buffer(buff);
			return -EIO;
		}
		desc->data += NET_IP_ALIGN;
		port->rx_buff_tab[i] = buff;
	}

	return 0;
}

static void destroy_queues(struct port *port)
{
	int i;

	if (port->desc_tab) {
		for (i = 0; i < RX_DESCS; i++) {
			struct desc *desc = rx_desc_ptr(port, i);
			buffer_t *buff = port->rx_buff_tab[i];
			if (buff) {
				dma_unmap_single(&port->netdev->dev,
						 desc->data - NET_IP_ALIGN,
						 RX_BUFF_SIZE, DMA_FROM_DEVICE);
				free_buffer(buff);
			}
		}
		for (i = 0; i < TX_DESCS; i++) {
			struct desc *desc = tx_desc_ptr(port, i);
			buffer_t *buff = port->tx_buff_tab[i];
			if (buff) {
				dma_unmap_tx(port, desc);
				free_buffer(buff);
			}
		}
		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
		port->desc_tab = NULL;
	}

	if (!ports_open && dma_pool) {
		dma_pool_destroy(dma_pool);
		dma_pool = NULL;
	}
}

static int ixp4xx_do_change_mtu(struct net_device *dev, int new_mtu)
{
	struct port *port = netdev_priv(dev);
	struct npe *npe = port->npe;
	int framesize, chunks;
	struct msg msg = {};

	/* adjust for ethernet headers */
	framesize = new_mtu + VLAN_ETH_HLEN;
	/* max rx/tx 64 byte chunks */
	chunks = DIV_ROUND_UP(framesize, 64);

	msg.cmd = NPE_SETMAXFRAMELENGTHS;
	msg.eth_id = port->id;

	/* Firmware wants to know buffer size in 64 byte chunks */
	msg.byte2 = chunks << 8;
	msg.byte3 = chunks << 8;

	msg.byte4 = msg.byte6 = framesize >> 8;
	msg.byte5 = msg.byte7 = framesize & 0xff;

	if (npe_send_recv_message(npe, &msg, "ETH_SET_MAX_FRAME_LENGTH"))
		return -EIO;
	netdev_dbg(dev, "set MTU on NPE %s to %d bytes\n",
		   npe_name(npe), new_mtu);

	return 0;
}

static int ixp4xx_eth_change_mtu(struct net_device *dev, int new_mtu)
{
	int ret;

	/* MTU can only be changed when the interface is up. We also
	 * set the MTU from dev->mtu when opening the device.
	 */
	if (dev->flags & IFF_UP) {
		ret = ixp4xx_do_change_mtu(dev, new_mtu);
		if (ret < 0)
			return ret;
	}

	WRITE_ONCE(dev->mtu, new_mtu);

	return 0;
}

static int eth_open(struct net_device *dev)
{
	struct port *port = netdev_priv(dev);
	struct npe *npe = port->npe;
	struct msg msg;
	int i, err;

	if (!npe_running(npe)) {
		err = npe_load_firmware(npe, npe_name(npe), &dev->dev);
		if (err)
			return err;

		if (npe_recv_message(npe, &msg, "ETH_GET_STATUS")) {
			netdev_err(dev, "%s not responding\n", npe_name(npe));
			return -EIO;
		}
		port->firmware[0] = msg.byte4;
		port->firmware[1] = msg.byte5;
		port->firmware[2] = msg.byte6;
		port->firmware[3] = msg.byte7;
	}

	memset(&msg, 0, sizeof(msg));
	msg.cmd = NPE_VLAN_SETRXQOSENTRY;
	msg.eth_id = port->id;
	msg.byte5 = port->plat->rxq | 0x80;
	msg.byte7 = port->plat->rxq << 4;
	for (i = 0; i < 8; i++) {
		msg.byte3 = i;
		if (npe_send_recv_message(port->npe, &msg, "ETH_SET_RXQ"))
			return -EIO;
	}

	msg.cmd = NPE_EDB_SETPORTADDRESS;
	msg.eth_id = PHYSICAL_ID(port->id);
	msg.byte2 = dev->dev_addr[0];
	msg.byte3 = dev->dev_addr[1];
	msg.byte4 = dev->dev_addr[2];
	msg.byte5 = dev->dev_addr[3];
	msg.byte6 = dev->dev_addr[4];
	msg.byte7 = dev->dev_addr[5];
	if (npe_send_recv_message(port->npe, &msg, "ETH_SET_MAC"))
		return -EIO;

	memset(&msg, 0, sizeof(msg));
	msg.cmd = NPE_FW_SETFIREWALLMODE;
	msg.eth_id = port->id;
	if (npe_send_recv_message(port->npe, &msg, "ETH_SET_FIREWALL_MODE"))
		return -EIO;

	ixp4xx_do_change_mtu(dev, dev->mtu);

	if ((err = request_queues(port)) != 0)
		return err;

	if ((err = init_queues(port)) != 0) {
		destroy_queues(port);
		release_queues(port);
		return err;
	}

	port->speed = 0;	/* force "link up" message */
	phy_start(dev->phydev);

	for (i = 0; i < ETH_ALEN; i++)
		__raw_writel(dev->dev_addr[i], &port->regs->hw_addr[i]);
	__raw_writel(0x08, &port->regs->random_seed);
	__raw_writel(0x12, &port->regs->partial_empty_threshold);
	__raw_writel(0x30, &port->regs->partial_full_threshold);
	__raw_writel(0x08, &port->regs->tx_start_bytes);
	__raw_writel(0x15, &port->regs->tx_deferral);
	__raw_writel(0x08, &port->regs->tx_2part_deferral[0]);
	__raw_writel(0x07, &port->regs->tx_2part_deferral[1]);
	__raw_writel(0x80, &port->regs->slot_time);
	__raw_writel(0x01, &port->regs->int_clock_threshold);

	/* Populate queues with buffers, no failure after this point */
	for (i = 0; i < TX_DESCS; i++)
		queue_put_desc(port->plat->txreadyq,
			       tx_desc_phys(port, i), tx_desc_ptr(port, i));

	for (i = 0; i < RX_DESCS; i++)
		queue_put_desc(RXFREE_QUEUE(port->id),
			       rx_desc_phys(port, i), rx_desc_ptr(port, i));

	__raw_writel(TX_CNTRL1_RETRIES, &port->regs->tx_control[1]);
	__raw_writel(DEFAULT_TX_CNTRL0, &port->regs->tx_control[0]);
	__raw_writel(0, &port->regs->rx_control[1]);
	__raw_writel(DEFAULT_RX_CNTRL0, &port->regs->rx_control[0]);

	napi_enable(&port->napi);
	eth_set_mcast_list(dev);
	netif_start_queue(dev);

	qmgr_set_irq(port->plat->rxq, QUEUE_IRQ_SRC_NOT_EMPTY,
		     eth_rx_irq, dev);
	if (!ports_open) {
		qmgr_set_irq(TXDONE_QUEUE, QUEUE_IRQ_SRC_NOT_EMPTY,
			     eth_txdone_irq, NULL);
		qmgr_enable_irq(TXDONE_QUEUE);
	}
	ports_open++;
	/* we may already have RX data, enables IRQ */
	napi_schedule(&port->napi);
	return 0;
}

static int eth_close(struct net_device *dev)
{
	struct port *port = netdev_priv(dev);
	struct msg msg;
	int buffs = RX_DESCS; /* allocated RX buffers */
	int i;

	ports_open--;
	qmgr_disable_irq(port->plat->rxq);
	napi_disable(&port->napi);
	netif_stop_queue(dev);

	while (queue_get_desc(RXFREE_QUEUE(port->id), port, 0) >= 0)
		buffs--;

	memset(&msg, 0, sizeof(msg));
	msg.cmd = NPE_SETLOOPBACK_MODE;
	msg.eth_id = port->id;
	msg.byte3 = 1;
	if (npe_send_recv_message(port->npe, &msg, "ETH_ENABLE_LOOPBACK"))
		netdev_crit(dev, "unable to enable loopback\n");

	i = 0;
	do {			/* drain RX buffers */
		while (queue_get_desc(port->plat->rxq, port, 0) >= 0)
			buffs--;
		if (!buffs)
			break;
		if (qmgr_stat_empty(TX_QUEUE(port->id))) {
			/* we have to inject some packet */
			struct desc *desc;
			u32 phys;
			int n = queue_get_desc(port->plat->txreadyq, port, 1);
			BUG_ON(n < 0);
			desc = tx_desc_ptr(port, n);
			phys = tx_desc_phys(port, n);
			desc->buf_len = desc->pkt_len = 1;
			wmb();
			queue_put_desc(TX_QUEUE(port->id), phys, desc);
		}
		udelay(1);
	} while (++i < MAX_CLOSE_WAIT);

	if (buffs)
		netdev_crit(dev, "unable to drain RX queue, %i buffer(s)"
			    " left in NPE\n", buffs);
#if DEBUG_CLOSE
	if (!buffs)
		netdev_debug(dev, "draining RX queue took %i cycles\n", i);
#endif

	buffs = TX_DESCS;
	while (queue_get_desc(TX_QUEUE(port->id), port, 1) >= 0)
		buffs--; /* cancel TX */

	i = 0;
	do {
		while (queue_get_desc(port->plat->txreadyq, port, 1) >= 0)
			buffs--;
		if (!buffs)
			break;
	} while (++i < MAX_CLOSE_WAIT);

	if (buffs)
		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) "
			    "left in NPE\n", buffs);
#if DEBUG_CLOSE
	if (!buffs)
		netdev_debug(dev, "draining TX queues took %i cycles\n", i);
#endif

	msg.byte3 = 0;
	if (npe_send_recv_message(port->npe, &msg, "ETH_DISABLE_LOOPBACK"))
		netdev_crit(dev, "unable to disable loopback\n");

	phy_stop(dev->phydev);

	if (!ports_open)
		qmgr_disable_irq(TXDONE_QUEUE);
	destroy_queues(port);
	release_queues(port);
	return 0;
}

static const struct net_device_ops ixp4xx_netdev_ops = {
	.ndo_open = eth_open,
	.ndo_stop = eth_close,
	.ndo_change_mtu = ixp4xx_eth_change_mtu,
	.ndo_start_xmit = eth_xmit,
	.ndo_set_rx_mode = eth_set_mcast_list,
	.ndo_eth_ioctl = eth_ioctl,
	.ndo_set_mac_address = eth_mac_addr,
	.ndo_validate_addr = eth_validate_addr,
};

static struct eth_plat_info *ixp4xx_of_get_platdata(struct device *dev)
{
	struct device_node *np = dev->of_node;
	struct of_phandle_args queue_spec;
	struct of_phandle_args npe_spec;
	struct device_node *mdio_np;
	struct eth_plat_info *plat;
	u8 mac[ETH_ALEN];
	int ret;

	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
	if (!plat)
		return NULL;

	ret = of_parse_phandle_with_fixed_args(np, "intel,npe-handle", 1, 0,
					       &npe_spec);
	if (ret) {
		dev_err(dev, "no NPE engine specified\n");
		return NULL;
	}
	/* NPE ID 0x00, 0x10, 0x20... */
	plat->npe = (npe_spec.args[0] << 4);

	/* Check if this device has an MDIO bus */
	mdio_np = of_get_child_by_name(np, "mdio");
	if (mdio_np) {
		plat->has_mdio = true;
		mdio_bus_np = mdio_np;
		/* DO NOT put the mdio_np, it will be used */
	}

	/* Get the rx queue as a resource from queue manager */
	ret = of_parse_phandle_with_fixed_args(np, "queue-rx", 1, 0,
					       &queue_spec);
	if (ret) {
		dev_err(dev, "no rx queue phandle\n");
		return NULL;
	}
	plat->rxq = queue_spec.args[0];

	/* Get the txready queue as resource from queue manager */
	ret = of_parse_phandle_with_fixed_args(np, "queue-txready", 1, 0,
					       &queue_spec);
	if (ret) {
		dev_err(dev, "no txready queue phandle\n");
		return NULL;
	}
	plat->txreadyq = queue_spec.args[0];

	ret = of_get_mac_address(np, mac);
	if (!ret) {
		dev_info(dev, "Setting macaddr from DT %pM\n", mac);
		memcpy(plat->hwaddr, mac, ETH_ALEN);
	}

	return plat;
}

static int ixp4xx_eth_probe(struct platform_device *pdev)
{
	struct phy_device *phydev = NULL;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct eth_plat_info *plat;
	struct net_device *ndev;
	struct port *port;
	int err;

	plat = ixp4xx_of_get_platdata(dev);
	if (!plat)
		return -ENODEV;

	if (!(ndev = devm_alloc_etherdev(dev, sizeof(struct port))))
		return -ENOMEM;

	SET_NETDEV_DEV(ndev, dev);
	port = netdev_priv(ndev);
	port->netdev = ndev;
	port->id = plat->npe;
	port->phc_index = -1;

	/* Get the port resource and remap */
	port->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
	if (IS_ERR(port->regs))
		return PTR_ERR(port->regs);

	/* Register the MDIO bus if we have it */
	if (plat->has_mdio) {
		err = ixp4xx_mdio_register(port->regs);
		if (err) {
			dev_err(dev, "failed to register MDIO bus\n");
			return err;
		}
	}
	/* If the instance with the MDIO bus has not yet appeared,
	 * defer probing until it gets probed.
	 */
	if (!mdio_bus)
		return -EPROBE_DEFER;

	ndev->netdev_ops = &ixp4xx_netdev_ops;
	ndev->ethtool_ops = &ixp4xx_ethtool_ops;
	ndev->tx_queue_len = 100;
	/* Inherit the DMA masks from the platform device */
	ndev->dev.dma_mask = dev->dma_mask;
	ndev->dev.coherent_dma_mask = dev->coherent_dma_mask;

	ndev->min_mtu = ETH_MIN_MTU;
	ndev->max_mtu = MAX_MRU;

	netif_napi_add_weight(ndev, &port->napi, eth_poll, NAPI_WEIGHT);

	if (!(port->npe = npe_request(NPE_ID(port->id))))
		return -EIO;

	port->plat = plat;
	npe_port_tab[NPE_ID(port->id)] = port;
	if (is_valid_ether_addr(plat->hwaddr))
		eth_hw_addr_set(ndev, plat->hwaddr);
	else
		eth_hw_addr_random(ndev);

	platform_set_drvdata(pdev, ndev);

	__raw_writel(DEFAULT_CORE_CNTRL | CORE_RESET,
		     &port->regs->core_control);
	udelay(50);
	__raw_writel(DEFAULT_CORE_CNTRL, &port->regs->core_control);
	udelay(50);

	phydev = of_phy_get_and_connect(ndev, np, ixp4xx_adjust_link);
	if (!phydev) {
		err = -ENODEV;
		dev_err(dev, "no phydev\n");
		goto err_free_mem;
	}

	phydev->irq = PHY_POLL;

	if ((err = register_netdev(ndev)))
		goto err_phy_dis;

	netdev_info(ndev, "%s: MII PHY %s on %s\n", ndev->name, phydev_name(phydev),
		    npe_name(port->npe));

	return 0;

err_phy_dis:
	phy_disconnect(phydev);
err_free_mem:
	npe_port_tab[NPE_ID(port->id)] = NULL;
	npe_release(port->npe);
	return err;
}

static void ixp4xx_eth_remove(struct platform_device *pdev)
{
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct phy_device *phydev = ndev->phydev;
	struct port *port = netdev_priv(ndev);

	unregister_netdev(ndev);
	phy_disconnect(phydev);
	ixp4xx_mdio_remove();
	npe_port_tab[NPE_ID(port->id)] = NULL;
	npe_release(port->npe);
}

static const struct of_device_id ixp4xx_eth_of_match[] = {
	{
		.compatible = "intel,ixp4xx-ethernet",
	},
	{ },
};

static struct platform_driver ixp4xx_eth_driver = {
	.driver = {
		.name = DRV_NAME,
		.of_match_table = of_match_ptr(ixp4xx_eth_of_match),
	},
	.probe		= ixp4xx_eth_probe,
	.remove_new	= ixp4xx_eth_remove,
};
module_platform_driver(ixp4xx_eth_driver);

MODULE_AUTHOR("Krzysztof Halasa");
MODULE_DESCRIPTION("Intel IXP4xx Ethernet driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:ixp4xx_eth");