text: /* drivers/net/ethernet/micrel/ks8851.c
   *
   * Copyright 2009 Simtec Electronics
   *	http://www.simtec.co.uk/
   *	Ben Dooks <ben@simtec.co.uk>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #define DEBUG
  
  #include <linux/interrupt.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/ethtool.h>
  #include <linux/cache.h>
  #include <linux/crc32.h>
  #include <linux/mii.h>
  #include <linux/eeprom_93cx6.h>
  #include <linux/regulator/consumer.h>
  
  #include <linux/spi/spi.h>
  #include <linux/gpio.h>
  #include <linux/of_gpio.h>
  
  #include "ks8851.h"
  
  /**
   * struct ks8851_rxctrl - KS8851 driver rx control
   * @mchash: Multicast hash-table data.
   * @rxcr1: KS_RXCR1 register setting
   * @rxcr2: KS_RXCR2 register setting
   *
   * Representation of the settings needs to control the receive filtering
   * such as the multicast hash-filter and the receive register settings. This
   * is used to make the job of working out if the receive settings change and
   * then issuing the new settings to the worker that will send the necessary
   * commands.
   */
  struct ks8851_rxctrl {
  	u16	mchash[4];
  	u16	rxcr1;
  	u16	rxcr2;
  };
  
  /**
   * union ks8851_tx_hdr - tx header data
   * @txb: The header as bytes
   * @txw: The header as 16bit, little-endian words
   *
   * A dual representation of the tx header data to allow
   * access to individual bytes, and to allow 16bit accesses
   * with 16bit alignment.
   */
  union ks8851_tx_hdr {
  	u8	txb[6];
  	__le16	txw[3];
  };
  
  /**
   * struct ks8851_net - KS8851 driver private data
   * @netdev: The network device we're bound to
   * @spidev: The spi device we're bound to.
   * @lock: Lock to ensure that the device is not accessed when busy.
   * @statelock: Lock on this structure for tx list.
   * @mii: The MII state information for the mii calls.
   * @rxctrl: RX settings for @rxctrl_work.
   * @tx_work: Work queue for tx packets
   * @rxctrl_work: Work queue for updating RX mode and multicast lists
   * @txq: Queue of packets for transmission.
   * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.
   * @spi_msg2: pre-setup SPI transfer with two messages, @spi_xfer2.
   * @txh: Space for generating packet TX header in DMA-able data
   * @rxd: Space for receiving SPI data, in DMA-able space.
   * @txd: Space for transmitting SPI data, in DMA-able space.
   * @msg_enable: The message flags controlling driver output (see ethtool).
   * @fid: Incrementing frame id tag.
   * @rc_ier: Cached copy of KS_IER.
   * @rc_ccr: Cached copy of KS_CCR.
   * @rc_rxqcr: Cached copy of KS_RXQCR.
   * @eeprom_size: Companion eeprom size in Bytes, 0 if no eeprom
   * @eeprom: 93CX6 EEPROM state for accessing on-board EEPROM.
   * @vdd_reg:	Optional regulator supplying the chip
   * @vdd_io: Optional digital power supply for IO
   * @gpio: Optional reset_n gpio
   *
   * The @lock ensures that the chip is protected when certain operations are
   * in progress. When the read or write packet transfer is in progress, most
   * of the chip registers are not ccessible until the transfer is finished and
   * the DMA has been de-asserted.
   *
   * The @statelock is used to protect information in the structure which may
   * need to be accessed via several sources, such as the network driver layer
   * or one of the work queues.
   *
   * We align the buffers we may use for rx/tx to ensure that if the SPI driver
   * wants to DMA map them, it will not have any problems with data the driver
   * modifies.
   */
  struct ks8851_net {
  	struct net_device	*netdev;
  	struct spi_device	*spidev;
  	struct mutex		lock;
  	spinlock_t		statelock;
  
  	union ks8851_tx_hdr	txh ____cacheline_aligned;
  	u8			rxd[8];
  	u8			txd[8];
  
  	u32			msg_enable ____cacheline_aligned;
  	u16			tx_space;
  	u8			fid;
  
  	u16			rc_ier;
  	u16			rc_rxqcr;
  	u16			rc_ccr;
  	u16			eeprom_size;
  
  	struct mii_if_info	mii;
  	struct ks8851_rxctrl	rxctrl;
  
  	struct work_struct	tx_work;
  	struct work_struct	rxctrl_work;
  
  	struct sk_buff_head	txq;
  
  	struct spi_message	spi_msg1;
  	struct spi_message	spi_msg2;
  	struct spi_transfer	spi_xfer1;
  	struct spi_transfer	spi_xfer2[2];
  
  	struct eeprom_93cx6	eeprom;
  	struct regulator	*vdd_reg;
  	struct regulator	*vdd_io;
  	int			gpio;
  };
  
  static int msg_enable;
  
  /* shift for byte-enable data */
  #define BYTE_EN(_x)	((_x) << 2)
  
  /* turn register number and byte-enable mask into data for start of packet */
  #define MK_OP(_byteen, _reg) (BYTE_EN(_byteen) | (_reg)  << (8+2) | (_reg) >> 6)
  
  /* SPI register read/write calls.
   *
   * All these calls issue SPI transactions to access the chip's registers. They
   * all require that the necessary lock is held to prevent accesses when the
   * chip is busy transferring packet data (RX/TX FIFO accesses).
   */
  
  /**
   * ks8851_wrreg16 - write 16bit register value to chip
   * @ks: The chip state
   * @reg: The register address
   * @val: The value to write
   *
   * Issue a write to put the value @val into the register specified in @reg.
   */
  static void ks8851_wrreg16(struct ks8851_net *ks, unsigned reg, unsigned val)
  {
  	struct spi_transfer *xfer = &ks->spi_xfer1;
  	struct spi_message *msg = &ks->spi_msg1;
  	__le16 txb[2];
  	int ret;
  
  	txb[0] = cpu_to_le16(MK_OP(reg & 2 ? 0xC : 0x03, reg) | KS_SPIOP_WR);
  	txb[1] = cpu_to_le16(val);
  
  	xfer->tx_buf = txb;
  	xfer->rx_buf = NULL;
  	xfer->len = 4;
  
  	ret = spi_sync(ks->spidev, msg);
  	if (ret < 0)
  		netdev_err(ks->netdev, "spi_sync() failed\n");
  }
  
  /**
   * ks8851_wrreg8 - write 8bit register value to chip
   * @ks: The chip state
   * @reg: The register address
   * @val: The value to write
   *
   * Issue a write to put the value @val into the register specified in @reg.
   */
  static void ks8851_wrreg8(struct ks8851_net *ks, unsigned reg, unsigned val)
  {
  	struct spi_transfer *xfer = &ks->spi_xfer1;
  	struct spi_message *msg = &ks->spi_msg1;
  	__le16 txb[2];
  	int ret;
  	int bit;
  
  	bit = 1 << (reg & 3);
  
  	txb[0] = cpu_to_le16(MK_OP(bit, reg) | KS_SPIOP_WR);
  	txb[1] = val;
  
  	xfer->tx_buf = txb;
  	xfer->rx_buf = NULL;
  	xfer->len = 3;
  
  	ret = spi_sync(ks->spidev, msg);
  	if (ret < 0)
  		netdev_err(ks->netdev, "spi_sync() failed\n");
  }
  
  /**
   * ks8851_rx_1msg - select whether to use one or two messages for spi read
   * @ks: The device structure
   *
   * Return whether to generate a single message with a tx and rx buffer
   * supplied to spi_sync(), or alternatively send the tx and rx buffers
   * as separate messages.
   *
   * Depending on the hardware in use, a single message may be more efficient
   * on interrupts or work done by the driver.
   *
   * This currently always returns true until we add some per-device data passed
   * from the platform code to specify which mode is better.
   */
  static inline bool ks8851_rx_1msg(struct ks8851_net *ks)
  {
  	return true;
  }
  
  /**
   * ks8851_rdreg - issue read register command and return the data
   * @ks: The device state
   * @op: The register address and byte enables in message format.
   * @rxb: The RX buffer to return the result into
   * @rxl: The length of data expected.
   *
   * This is the low level read call that issues the necessary spi message(s)
   * to read data from the register specified in @op.
   */
  static void ks8851_rdreg(struct ks8851_net *ks, unsigned op,
  			 u8 *rxb, unsigned rxl)
  {
  	struct spi_transfer *xfer;
  	struct spi_message *msg;
  	__le16 *txb = (__le16 *)ks->txd;
  	u8 *trx = ks->rxd;
  	int ret;
  
  	txb[0] = cpu_to_le16(op | KS_SPIOP_RD);
  
  	if (ks8851_rx_1msg(ks)) {
  		msg = &ks->spi_msg1;
  		xfer = &ks->spi_xfer1;
  
  		xfer->tx_buf = txb;
  		xfer->rx_buf = trx;
  		xfer->len = rxl + 2;
  	} else {
  		msg = &ks->spi_msg2;
  		xfer = ks->spi_xfer2;
  
  		xfer->tx_buf = txb;
  		xfer->rx_buf = NULL;
  		xfer->len = 2;
  
  		xfer++;
  		xfer->tx_buf = NULL;
  		xfer->rx_buf = trx;
  		xfer->len = rxl;
  	}
  
  	ret = spi_sync(ks->spidev, msg);
  	if (ret < 0)
  		netdev_err(ks->netdev, "read: spi_sync() failed\n");
  	else if (ks8851_rx_1msg(ks))
  		memcpy(rxb, trx + 2, rxl);
  	else
  		memcpy(rxb, trx, rxl);
  }
  
  /**
   * ks8851_rdreg8 - read 8 bit register from device
   * @ks: The chip information
   * @reg: The register address
   *
   * Read a 8bit register from the chip, returning the result
  */
  static unsigned ks8851_rdreg8(struct ks8851_net *ks, unsigned reg)
  {
  	u8 rxb[1];
  
  	ks8851_rdreg(ks, MK_OP(1 << (reg & 3), reg), rxb, 1);
  	return rxb[0];
  }
  
  /**
   * ks8851_rdreg16 - read 16 bit register from device
   * @ks: The chip information
   * @reg: The register address
   *
   * Read a 16bit register from the chip, returning the result
  */
  static unsigned ks8851_rdreg16(struct ks8851_net *ks, unsigned reg)
  {
  	__le16 rx = 0;
  
  	ks8851_rdreg(ks, MK_OP(reg & 2 ? 0xC : 0x3, reg), (u8 *)&rx, 2);
  	return le16_to_cpu(rx);
  }
  
  /**
   * ks8851_rdreg32 - read 32 bit register from device
   * @ks: The chip information
   * @reg: The register address
   *
   * Read a 32bit register from the chip.
   *
   * Note, this read requires the address be aligned to 4 bytes.
  */
  static unsigned ks8851_rdreg32(struct ks8851_net *ks, unsigned reg)
  {
  	__le32 rx = 0;
  
  	WARN_ON(reg & 3);
  
  	ks8851_rdreg(ks, MK_OP(0xf, reg), (u8 *)&rx, 4);
  	return le32_to_cpu(rx);
  }
  
  /**
   * ks8851_soft_reset - issue one of the soft reset to the device
   * @ks: The device state.
   * @op: The bit(s) to set in the GRR
   *
   * Issue the relevant soft-reset command to the device's GRR register
   * specified by @op.
   *
   * Note, the delays are in there as a caution to ensure that the reset
   * has time to take effect and then complete. Since the datasheet does
   * not currently specify the exact sequence, we have chosen something
   * that seems to work with our device.
   */
  static void ks8851_soft_reset(struct ks8851_net *ks, unsigned op)
  {
  	ks8851_wrreg16(ks, KS_GRR, op);
  	mdelay(1);	/* wait a short time to effect reset */
  	ks8851_wrreg16(ks, KS_GRR, 0);
  	mdelay(1);	/* wait for condition to clear */
  }
  
  /**
   * ks8851_set_powermode - set power mode of the device
   * @ks: The device state
   * @pwrmode: The power mode value to write to KS_PMECR.
   *
   * Change the power mode of the chip.
   */
  static void ks8851_set_powermode(struct ks8851_net *ks, unsigned pwrmode)
  {
  	unsigned pmecr;
  
  	netif_dbg(ks, hw, ks->netdev, "setting power mode %d\n", pwrmode);
  
  	pmecr = ks8851_rdreg16(ks, KS_PMECR);
  	pmecr &= ~PMECR_PM_MASK;
  	pmecr |= pwrmode;
  
  	ks8851_wrreg16(ks, KS_PMECR, pmecr);
  }
  
  /**
   * ks8851_write_mac_addr - write mac address to device registers
   * @dev: The network device
   *
   * Update the KS8851 MAC address registers from the address in @dev.
   *
   * This call assumes that the chip is not running, so there is no need to
   * shutdown the RXQ process whilst setting this.
  */
  static int ks8851_write_mac_addr(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	int i;
  
  	mutex_lock(&ks->lock);
  
  	/*
  	 * Wake up chip in case it was powered off when stopped; otherwise,
  	 * the first write to the MAC address does not take effect.
  	 */
  	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
  	for (i = 0; i < ETH_ALEN; i++)
  		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
  	if (!netif_running(dev))
  		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
  
  	mutex_unlock(&ks->lock);
  
  	return 0;
  }
  
  /**
   * ks8851_read_mac_addr - read mac address from device registers
   * @dev: The network device
   *
   * Update our copy of the KS8851 MAC address from the registers of @dev.
  */
  static void ks8851_read_mac_addr(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	int i;
  
  	mutex_lock(&ks->lock);
  
  	for (i = 0; i < ETH_ALEN; i++)
  		dev->dev_addr[i] = ks8851_rdreg8(ks, KS_MAR(i));
  
  	mutex_unlock(&ks->lock);
  }
  
  /**
   * ks8851_init_mac - initialise the mac address
   * @ks: The device structure
   *
   * Get or create the initial mac address for the device and then set that
   * into the station address register. If there is an EEPROM present, then
   * we try that. If no valid mac address is found we use eth_random_addr()
   * to create a new one.
   */
  static void ks8851_init_mac(struct ks8851_net *ks)
  {
  	struct net_device *dev = ks->netdev;
  
  	/* first, try reading what we've got already */
  	if (ks->rc_ccr & CCR_EEPROM) {
  		ks8851_read_mac_addr(dev);
  		if (is_valid_ether_addr(dev->dev_addr))
  			return;
  
  		netdev_err(ks->netdev, "invalid mac address read %pM\n",
  				dev->dev_addr);
  	}
  
  	eth_hw_addr_random(dev);
  	ks8851_write_mac_addr(dev);
  }
  
  /**
   * ks8851_rdfifo - read data from the receive fifo
   * @ks: The device state.
   * @buff: The buffer address
   * @len: The length of the data to read
   *
   * Issue an RXQ FIFO read command and read the @len amount of data from
   * the FIFO into the buffer specified by @buff.
   */
  static void ks8851_rdfifo(struct ks8851_net *ks, u8 *buff, unsigned len)
  {
  	struct spi_transfer *xfer = ks->spi_xfer2;
  	struct spi_message *msg = &ks->spi_msg2;
  	u8 txb[1];
  	int ret;
  
  	netif_dbg(ks, rx_status, ks->netdev,
  		  "%s: %d@%p\n", __func__, len, buff);
  
  	/* set the operation we're issuing */
  	txb[0] = KS_SPIOP_RXFIFO;
  
  	xfer->tx_buf = txb;
  	xfer->rx_buf = NULL;
  	xfer->len = 1;
  
  	xfer++;
  	xfer->rx_buf = buff;
  	xfer->tx_buf = NULL;
  	xfer->len = len;
  
  	ret = spi_sync(ks->spidev, msg);
  	if (ret < 0)
  		netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
  }
  
  /**
   * ks8851_dbg_dumpkkt - dump initial packet contents to debug
   * @ks: The device state
   * @rxpkt: The data for the received packet
   *
   * Dump the initial data from the packet to dev_dbg().
  */
  static void ks8851_dbg_dumpkkt(struct ks8851_net *ks, u8 *rxpkt)
  {
  	netdev_dbg(ks->netdev,
  		   "pkt %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x\n",
  		   rxpkt[4], rxpkt[5], rxpkt[6], rxpkt[7],
  		   rxpkt[8], rxpkt[9], rxpkt[10], rxpkt[11],
  		   rxpkt[12], rxpkt[13], rxpkt[14], rxpkt[15]);
  }
  
  /**
   * ks8851_rx_pkts - receive packets from the host
   * @ks: The device information.
   *
   * This is called from the IRQ work queue when the system detects that there
   * are packets in the receive queue. Find out how many packets there are and
   * read them from the FIFO.
   */
  static void ks8851_rx_pkts(struct ks8851_net *ks)
  {
  	struct sk_buff *skb;
  	unsigned rxfc;
  	unsigned rxlen;
  	unsigned rxstat;
  	u32 rxh;
  	u8 *rxpkt;
  
  	rxfc = ks8851_rdreg8(ks, KS_RXFC);
  
  	netif_dbg(ks, rx_status, ks->netdev,
  		  "%s: %d packets\n", __func__, rxfc);
  
  	/* Currently we're issuing a read per packet, but we could possibly
  	 * improve the code by issuing a single read, getting the receive
  	 * header, allocating the packet and then reading the packet data
  	 * out in one go.
  	 *
  	 * This form of operation would require us to hold the SPI bus'
  	 * chipselect low during the entie transaction to avoid any
  	 * reset to the data stream coming from the chip.
  	 */
  
  	for (; rxfc != 0; rxfc--) {
  		rxh = ks8851_rdreg32(ks, KS_RXFHSR);
  		rxstat = rxh & 0xffff;
  		rxlen = (rxh >> 16) & 0xfff;
  
  		netif_dbg(ks, rx_status, ks->netdev,
  			  "rx: stat 0x%04x, len 0x%04x\n", rxstat, rxlen);
  
  		/* the length of the packet includes the 32bit CRC */
  
  		/* set dma read address */
  		ks8851_wrreg16(ks, KS_RXFDPR, RXFDPR_RXFPAI | 0x00);
  
  		/* start the packet dma process, and set auto-dequeue rx */
  		ks8851_wrreg16(ks, KS_RXQCR,
  			       ks->rc_rxqcr | RXQCR_SDA | RXQCR_ADRFE);
  
  		if (rxlen > 4) {
  			unsigned int rxalign;
  
  			rxlen -= 4;
  			rxalign = ALIGN(rxlen, 4);
  			skb = netdev_alloc_skb_ip_align(ks->netdev, rxalign);
  			if (skb) {
  
  				/* 4 bytes of status header + 4 bytes of
  				 * garbage: we put them before ethernet
  				 * header, so that they are copied,
  				 * but ignored.
  				 */
  
  				rxpkt = skb_put(skb, rxlen) - 8;
  
  				ks8851_rdfifo(ks, rxpkt, rxalign + 8);
  
  				if (netif_msg_pktdata(ks))
  					ks8851_dbg_dumpkkt(ks, rxpkt);
  
  				skb->protocol = eth_type_trans(skb, ks->netdev);
  				netif_rx_ni(skb);
  
  				ks->netdev->stats.rx_packets++;
  				ks->netdev->stats.rx_bytes += rxlen;
  			}
  		}
  
  		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
  	}
  }
  
  /**
   * ks8851_irq - IRQ handler for dealing with interrupt requests
   * @irq: IRQ number
   * @_ks: cookie
   *
   * This handler is invoked when the IRQ line asserts to find out what happened.
   * As we cannot allow ourselves to sleep in HARDIRQ context, this handler runs
   * in thread context.
   *
   * Read the interrupt status, work out what needs to be done and then clear
   * any of the interrupts that are not needed.
   */
  static irqreturn_t ks8851_irq(int irq, void *_ks)
  {
  	struct ks8851_net *ks = _ks;
  	unsigned status;
  	unsigned handled = 0;
  
  	mutex_lock(&ks->lock);
  
  	status = ks8851_rdreg16(ks, KS_ISR);
  
  	netif_dbg(ks, intr, ks->netdev,
  		  "%s: status 0x%04x\n", __func__, status);
  
  	if (status & IRQ_LCI)
  		handled |= IRQ_LCI;
  
  	if (status & IRQ_LDI) {
  		u16 pmecr = ks8851_rdreg16(ks, KS_PMECR);
  		pmecr &= ~PMECR_WKEVT_MASK;
  		ks8851_wrreg16(ks, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
  
  		handled |= IRQ_LDI;
  	}
  
  	if (status & IRQ_RXPSI)
  		handled |= IRQ_RXPSI;
  
  	if (status & IRQ_TXI) {
  		handled |= IRQ_TXI;
  
  		/* no lock here, tx queue should have been stopped */
  
  		/* update our idea of how much tx space is available to the
  		 * system */
  		ks->tx_space = ks8851_rdreg16(ks, KS_TXMIR);
  
  		netif_dbg(ks, intr, ks->netdev,
  			  "%s: txspace %d\n", __func__, ks->tx_space);
  	}
  
  	if (status & IRQ_RXI)
  		handled |= IRQ_RXI;
  
  	if (status & IRQ_SPIBEI) {
  		dev_err(&ks->spidev->dev, "%s: spi bus error\n", __func__);
  		handled |= IRQ_SPIBEI;
  	}
  
  	ks8851_wrreg16(ks, KS_ISR, handled);
  
  	if (status & IRQ_RXI) {
  		/* the datasheet says to disable the rx interrupt during
  		 * packet read-out, however we're masking the interrupt
  		 * from the device so do not bother masking just the RX
  		 * from the device. */
  
  		ks8851_rx_pkts(ks);
  	}
  
  	/* if something stopped the rx process, probably due to wanting
  	 * to change the rx settings, then do something about restarting
  	 * it. */
  	if (status & IRQ_RXPSI) {
  		struct ks8851_rxctrl *rxc = &ks->rxctrl;
  
  		/* update the multicast hash table */
  		ks8851_wrreg16(ks, KS_MAHTR0, rxc->mchash[0]);
  		ks8851_wrreg16(ks, KS_MAHTR1, rxc->mchash[1]);
  		ks8851_wrreg16(ks, KS_MAHTR2, rxc->mchash[2]);
  		ks8851_wrreg16(ks, KS_MAHTR3, rxc->mchash[3]);
  
  		ks8851_wrreg16(ks, KS_RXCR2, rxc->rxcr2);
  		ks8851_wrreg16(ks, KS_RXCR1, rxc->rxcr1);
  	}
  
  	mutex_unlock(&ks->lock);
  
  	if (status & IRQ_LCI)
  		mii_check_link(&ks->mii);
  
  	if (status & IRQ_TXI)
  		netif_wake_queue(ks->netdev);
  
  	return IRQ_HANDLED;
  }
  
  /**
   * calc_txlen - calculate size of message to send packet
   * @len: Length of data
   *
   * Returns the size of the TXFIFO message needed to send
   * this packet.
   */
  static inline unsigned calc_txlen(unsigned len)
  {
  	return ALIGN(len + 4, 4);
  }
  
  /**
   * ks8851_wrpkt - write packet to TX FIFO
   * @ks: The device state.
   * @txp: The sk_buff to transmit.
   * @irq: IRQ on completion of the packet.
   *
   * Send the @txp to the chip. This means creating the relevant packet header
   * specifying the length of the packet and the other information the chip
   * needs, such as IRQ on completion. Send the header and the packet data to
   * the device.
   */
  static void ks8851_wrpkt(struct ks8851_net *ks, struct sk_buff *txp, bool irq)
  {
  	struct spi_transfer *xfer = ks->spi_xfer2;
  	struct spi_message *msg = &ks->spi_msg2;
  	unsigned fid = 0;
  	int ret;
  
  	netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n",
  		  __func__, txp, txp->len, txp->data, irq);
  
  	fid = ks->fid++;
  	fid &= TXFR_TXFID_MASK;
  
  	if (irq)
  		fid |= TXFR_TXIC;	/* irq on completion */
  
  	/* start header at txb[1] to align txw entries */
  	ks->txh.txb[1] = KS_SPIOP_TXFIFO;
  	ks->txh.txw[1] = cpu_to_le16(fid);
  	ks->txh.txw[2] = cpu_to_le16(txp->len);
  
  	xfer->tx_buf = &ks->txh.txb[1];
  	xfer->rx_buf = NULL;
  	xfer->len = 5;
  
  	xfer++;
  	xfer->tx_buf = txp->data;
  	xfer->rx_buf = NULL;
  	xfer->len = ALIGN(txp->len, 4);
  
  	ret = spi_sync(ks->spidev, msg);
  	if (ret < 0)
  		netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
  }
  
  /**
   * ks8851_done_tx - update and then free skbuff after transmitting
   * @ks: The device state
   * @txb: The buffer transmitted
   */
  static void ks8851_done_tx(struct ks8851_net *ks, struct sk_buff *txb)
  {
  	struct net_device *dev = ks->netdev;
  
  	dev->stats.tx_bytes += txb->len;
  	dev->stats.tx_packets++;
  
  	dev_kfree_skb(txb);
  }
  
  /**
   * ks8851_tx_work - process tx packet(s)
   * @work: The work strucutre what was scheduled.
   *
   * This is called when a number of packets have been scheduled for
   * transmission and need to be sent to the device.
   */
  static void ks8851_tx_work(struct work_struct *work)
  {
  	struct ks8851_net *ks = container_of(work, struct ks8851_net, tx_work);
  	struct sk_buff *txb;
  	bool last = skb_queue_empty(&ks->txq);
  
  	mutex_lock(&ks->lock);
  
  	while (!last) {
  		txb = skb_dequeue(&ks->txq);
  		last = skb_queue_empty(&ks->txq);
  
  		if (txb != NULL) {
  			ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
  			ks8851_wrpkt(ks, txb, last);
  			ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
  			ks8851_wrreg16(ks, KS_TXQCR, TXQCR_METFE);
  
  			ks8851_done_tx(ks, txb);
  		}
  	}
  
  	mutex_unlock(&ks->lock);
  }
  
  /**
   * ks8851_net_open - open network device
   * @dev: The network device being opened.
   *
   * Called when the network device is marked active, such as a user executing
   * 'ifconfig up' on the device.
   */
  static int ks8851_net_open(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  
  	/* lock the card, even if we may not actually be doing anything
  	 * else at the moment */
  	mutex_lock(&ks->lock);
  
  	netif_dbg(ks, ifup, ks->netdev, "opening\n");
  
  	/* bring chip out of any power saving mode it was in */
  	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
  
  	/* issue a soft reset to the RX/TX QMU to put it into a known
  	 * state. */
  	ks8851_soft_reset(ks, GRR_QMU);
  
  	/* setup transmission parameters */
  
  	ks8851_wrreg16(ks, KS_TXCR, (TXCR_TXE | /* enable transmit process */
  				     TXCR_TXPE | /* pad to min length */
  				     TXCR_TXCRC | /* add CRC */
  				     TXCR_TXFCE)); /* enable flow control */
  
  	/* auto-increment tx data, reset tx pointer */
  	ks8851_wrreg16(ks, KS_TXFDPR, TXFDPR_TXFPAI);
  
  	/* setup receiver control */
  
  	ks8851_wrreg16(ks, KS_RXCR1, (RXCR1_RXPAFMA | /*  from mac filter */
  				      RXCR1_RXFCE | /* enable flow control */
  				      RXCR1_RXBE | /* broadcast enable */
  				      RXCR1_RXUE | /* unicast enable */
  				      RXCR1_RXE)); /* enable rx block */
  
  	/* transfer entire frames out in one go */
  	ks8851_wrreg16(ks, KS_RXCR2, RXCR2_SRDBL_FRAME);
  
  	/* set receive counter timeouts */
  	ks8851_wrreg16(ks, KS_RXDTTR, 1000); /* 1ms after first frame to IRQ */
  	ks8851_wrreg16(ks, KS_RXDBCTR, 4096); /* >4Kbytes in buffer to IRQ */
  	ks8851_wrreg16(ks, KS_RXFCTR, 10);  /* 10 frames to IRQ */
  
  	ks->rc_rxqcr = (RXQCR_RXFCTE |  /* IRQ on frame count exceeded */
  			RXQCR_RXDBCTE | /* IRQ on byte count exceeded */
  			RXQCR_RXDTTE);  /* IRQ on time exceeded */
  
  	ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
  
  	/* clear then enable interrupts */
  
  #define STD_IRQ (IRQ_LCI |	/* Link Change */	\
  		 IRQ_TXI |	/* TX done */		\
  		 IRQ_RXI |	/* RX done */		\
  		 IRQ_SPIBEI |	/* SPI bus error */	\
  		 IRQ_TXPSI |	/* TX process stop */	\
  		 IRQ_RXPSI)	/* RX process stop */
  
  	ks->rc_ier = STD_IRQ;
  	ks8851_wrreg16(ks, KS_ISR, STD_IRQ);
  	ks8851_wrreg16(ks, KS_IER, STD_IRQ);
  
  	netif_start_queue(ks->netdev);
  
  	netif_dbg(ks, ifup, ks->netdev, "network device up\n");
  
  	mutex_unlock(&ks->lock);
  	return 0;
  }
  
  /**
   * ks8851_net_stop - close network device
   * @dev: The device being closed.
   *
   * Called to close down a network device which has been active. Cancell any
   * work, shutdown the RX and TX process and then place the chip into a low
   * power state whilst it is not being used.
   */
  static int ks8851_net_stop(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  
  	netif_info(ks, ifdown, dev, "shutting down\n");
  
  	netif_stop_queue(dev);
  
  	mutex_lock(&ks->lock);
  	/* turn off the IRQs and ack any outstanding */
  	ks8851_wrreg16(ks, KS_IER, 0x0000);
  	ks8851_wrreg16(ks, KS_ISR, 0xffff);
  	mutex_unlock(&ks->lock);
  
  	/* stop any outstanding work */
  	flush_work(&ks->tx_work);
  	flush_work(&ks->rxctrl_work);
  
  	mutex_lock(&ks->lock);
  	/* shutdown RX process */
  	ks8851_wrreg16(ks, KS_RXCR1, 0x0000);
  
  	/* shutdown TX process */
  	ks8851_wrreg16(ks, KS_TXCR, 0x0000);
  
  	/* set powermode to soft power down to save power */
  	ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
  	mutex_unlock(&ks->lock);
  
  	/* ensure any queued tx buffers are dumped */
  	while (!skb_queue_empty(&ks->txq)) {
  		struct sk_buff *txb = skb_dequeue(&ks->txq);
  
  		netif_dbg(ks, ifdown, ks->netdev,
  			  "%s: freeing txb %p\n", __func__, txb);
  
  		dev_kfree_skb(txb);
  	}
  
  	return 0;
  }
  
  /**
   * ks8851_start_xmit - transmit packet
   * @skb: The buffer to transmit
   * @dev: The device used to transmit the packet.
   *
   * Called by the network layer to transmit the @skb. Queue the packet for
   * the device and schedule the necessary work to transmit the packet when
   * it is free.
   *
   * We do this to firstly avoid sleeping with the network device locked,
   * and secondly so we can round up more than one packet to transmit which
   * means we can try and avoid generating too many transmit done interrupts.
   */
  static netdev_tx_t ks8851_start_xmit(struct sk_buff *skb,
  				     struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	unsigned needed = calc_txlen(skb->len);
  	netdev_tx_t ret = NETDEV_TX_OK;
  
  	netif_dbg(ks, tx_queued, ks->netdev,
  		  "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
  
  	spin_lock(&ks->statelock);
  
  	if (needed > ks->tx_space) {
  		netif_stop_queue(dev);
  		ret = NETDEV_TX_BUSY;
  	} else {
  		ks->tx_space -= needed;
  		skb_queue_tail(&ks->txq, skb);
  	}
  
  	spin_unlock(&ks->statelock);
  	schedule_work(&ks->tx_work);
  
  	return ret;
  }
  
  /**
   * ks8851_rxctrl_work - work handler to change rx mode
   * @work: The work structure this belongs to.
   *
   * Lock the device and issue the necessary changes to the receive mode from
   * the network device layer. This is done so that we can do this without
   * having to sleep whilst holding the network device lock.
   *
   * Since the recommendation from Micrel is that the RXQ is shutdown whilst the
   * receive parameters are programmed, we issue a write to disable the RXQ and
   * then wait for the interrupt handler to be triggered once the RXQ shutdown is
   * complete. The interrupt handler then writes the new values into the chip.
   */
  static void ks8851_rxctrl_work(struct work_struct *work)
  {
  	struct ks8851_net *ks = container_of(work, struct ks8851_net, rxctrl_work);
  
  	mutex_lock(&ks->lock);
  
  	/* need to shutdown RXQ before modifying filter parameters */
  	ks8851_wrreg16(ks, KS_RXCR1, 0x00);
  
  	mutex_unlock(&ks->lock);
  }
  
  static void ks8851_set_rx_mode(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	struct ks8851_rxctrl rxctrl;
  
  	memset(&rxctrl, 0, sizeof(rxctrl));
  
  	if (dev->flags & IFF_PROMISC) {
  		/* interface to receive everything */
  
  		rxctrl.rxcr1 = RXCR1_RXAE | RXCR1_RXINVF;
  	} else if (dev->flags & IFF_ALLMULTI) {
  		/* accept all multicast packets */
  
  		rxctrl.rxcr1 = (RXCR1_RXME | RXCR1_RXAE |
  				RXCR1_RXPAFMA | RXCR1_RXMAFMA);
  	} else if (dev->flags & IFF_MULTICAST && !netdev_mc_empty(dev)) {
  		struct netdev_hw_addr *ha;
  		u32 crc;
  
  		/* accept some multicast */
  
  		netdev_for_each_mc_addr(ha, dev) {
  			crc = ether_crc(ETH_ALEN, ha->addr);
  			crc >>= (32 - 6);  /* get top six bits */
  
  			rxctrl.mchash[crc >> 4] |= (1 << (crc & 0xf));
  		}
  
  		rxctrl.rxcr1 = RXCR1_RXME | RXCR1_RXPAFMA;
  	} else {
  		/* just accept broadcast / unicast */
  		rxctrl.rxcr1 = RXCR1_RXPAFMA;
  	}
  
  	rxctrl.rxcr1 |= (RXCR1_RXUE | /* unicast enable */
  			 RXCR1_RXBE | /* broadcast enable */
  			 RXCR1_RXE | /* RX process enable */
  			 RXCR1_RXFCE); /* enable flow control */
  
  	rxctrl.rxcr2 |= RXCR2_SRDBL_FRAME;
  
  	/* schedule work to do the actual set of the data if needed */
  
  	spin_lock(&ks->statelock);
  
  	if (memcmp(&rxctrl, &ks->rxctrl, sizeof(rxctrl)) != 0) {
  		memcpy(&ks->rxctrl, &rxctrl, sizeof(ks->rxctrl));
  		schedule_work(&ks->rxctrl_work);
  	}
  
  	spin_unlock(&ks->statelock);
  }
  
  static int ks8851_set_mac_address(struct net_device *dev, void *addr)
  {
  	struct sockaddr *sa = addr;
  
  	if (netif_running(dev))
  		return -EBUSY;
  
  	if (!is_valid_ether_addr(sa->sa_data))
  		return -EADDRNOTAVAIL;
  
  	memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
  	return ks8851_write_mac_addr(dev);
  }
  
  static int ks8851_net_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  
  	if (!netif_running(dev))
  		return -EINVAL;
  
  	return generic_mii_ioctl(&ks->mii, if_mii(req), cmd, NULL);
  }
  
  static const struct net_device_ops ks8851_netdev_ops = {
  	.ndo_open		= ks8851_net_open,
  	.ndo_stop		= ks8851_net_stop,
  	.ndo_do_ioctl		= ks8851_net_ioctl,
  	.ndo_start_xmit		= ks8851_start_xmit,
  	.ndo_set_mac_address	= ks8851_set_mac_address,
  	.ndo_set_rx_mode	= ks8851_set_rx_mode,
  	.ndo_change_mtu		= eth_change_mtu,
  	.ndo_validate_addr	= eth_validate_addr,
  };
  
  /* ethtool support */
  
  static void ks8851_get_drvinfo(struct net_device *dev,
  			       struct ethtool_drvinfo *di)
  {
  	strlcpy(di->driver, "KS8851", sizeof(di->driver));
  	strlcpy(di->version, "1.00", sizeof(di->version));
  	strlcpy(di->bus_info, dev_name(dev->dev.parent), sizeof(di->bus_info));
  }
  
  static u32 ks8851_get_msglevel(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	return ks->msg_enable;
  }
  
  static void ks8851_set_msglevel(struct net_device *dev, u32 to)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	ks->msg_enable = to;
  }
  
  static int ks8851_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	return mii_ethtool_gset(&ks->mii, cmd);
  }
  
  static int ks8851_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	return mii_ethtool_sset(&ks->mii, cmd);
  }
  
  static u32 ks8851_get_link(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	return mii_link_ok(&ks->mii);
  }
  
  static int ks8851_nway_reset(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	return mii_nway_restart(&ks->mii);
  }
  
  /* EEPROM support */
  
  static void ks8851_eeprom_regread(struct eeprom_93cx6 *ee)
  {
  	struct ks8851_net *ks = ee->data;
  	unsigned val;
  
  	val = ks8851_rdreg16(ks, KS_EEPCR);
  
  	ee->reg_data_out = (val & EEPCR_EESB) ? 1 : 0;
  	ee->reg_data_clock = (val & EEPCR_EESCK) ? 1 : 0;
  	ee->reg_chip_select = (val & EEPCR_EECS) ? 1 : 0;
  }
  
  static void ks8851_eeprom_regwrite(struct eeprom_93cx6 *ee)
  {
  	struct ks8851_net *ks = ee->data;
  	unsigned val = EEPCR_EESA;	/* default - eeprom access on */
  
  	if (ee->drive_data)
  		val |= EEPCR_EESRWA;
  	if (ee->reg_data_in)
  		val |= EEPCR_EEDO;
  	if (ee->reg_data_clock)
  		val |= EEPCR_EESCK;
  	if (ee->reg_chip_select)
  		val |= EEPCR_EECS;
  
  	ks8851_wrreg16(ks, KS_EEPCR, val);
  }
  
  /**
   * ks8851_eeprom_claim - claim device EEPROM and activate the interface
   * @ks: The network device state.
   *
   * Check for the presence of an EEPROM, and then activate software access
   * to the device.
   */
  static int ks8851_eeprom_claim(struct ks8851_net *ks)
  {
  	if (!(ks->rc_ccr & CCR_EEPROM))
  		return -ENOENT;
  
  	mutex_lock(&ks->lock);
  
  	/* start with clock low, cs high */
  	ks8851_wrreg16(ks, KS_EEPCR, EEPCR_EESA | EEPCR_EECS);
  	return 0;
  }
  
  /**
   * ks8851_eeprom_release - release the EEPROM interface
   * @ks: The device state
   *
   * Release the software access to the device EEPROM
   */
  static void ks8851_eeprom_release(struct ks8851_net *ks)
  {
  	unsigned val = ks8851_rdreg16(ks, KS_EEPCR);
  
  	ks8851_wrreg16(ks, KS_EEPCR, val & ~EEPCR_EESA);
  	mutex_unlock(&ks->lock);
  }
  
  #define KS_EEPROM_MAGIC (0x00008851)
  
  static int ks8851_set_eeprom(struct net_device *dev,
  			     struct ethtool_eeprom *ee, u8 *data)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	int offset = ee->offset;
  	int len = ee->len;
  	u16 tmp;
  
  	/* currently only support byte writing */
  	if (len != 1)
  		return -EINVAL;
  
  	if (ee->magic != KS_EEPROM_MAGIC)
  		return -EINVAL;
  
  	if (ks8851_eeprom_claim(ks))
  		return -ENOENT;
  
  	eeprom_93cx6_wren(&ks->eeprom, true);
  
  	/* ethtool currently only supports writing bytes, which means
  	 * we have to read/modify/write our 16bit EEPROMs */
  
  	eeprom_93cx6_read(&ks->eeprom, offset/2, &tmp);
  
  	if (offset & 1) {
  		tmp &= 0xff;
  		tmp |= *data << 8;
  	} else {
  		tmp &= 0xff00;
  		tmp |= *data;
  	}
  
  	eeprom_93cx6_write(&ks->eeprom, offset/2, tmp);
  	eeprom_93cx6_wren(&ks->eeprom, false);
  
  	ks8851_eeprom_release(ks);
  
  	return 0;
  }
  
  static int ks8851_get_eeprom(struct net_device *dev,
  			     struct ethtool_eeprom *ee, u8 *data)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	int offset = ee->offset;
  	int len = ee->len;
  
  	/* must be 2 byte aligned */
  	if (len & 1 || offset & 1)
  		return -EINVAL;
  
  	if (ks8851_eeprom_claim(ks))
  		return -ENOENT;
  
  	ee->magic = KS_EEPROM_MAGIC;
  
  	eeprom_93cx6_multiread(&ks->eeprom, offset/2, (__le16 *)data, len/2);
  	ks8851_eeprom_release(ks);
  
  	return 0;
  }
  
  static int ks8851_get_eeprom_len(struct net_device *dev)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  
  	/* currently, we assume it is an 93C46 attached, so return 128 */
  	return ks->rc_ccr & CCR_EEPROM ? 128 : 0;
  }
  
  static const struct ethtool_ops ks8851_ethtool_ops = {
  	.get_drvinfo	= ks8851_get_drvinfo,
  	.get_msglevel	= ks8851_get_msglevel,
  	.set_msglevel	= ks8851_set_msglevel,
  	.get_settings	= ks8851_get_settings,
  	.set_settings	= ks8851_set_settings,
  	.get_link	= ks8851_get_link,
  	.nway_reset	= ks8851_nway_reset,
  	.get_eeprom_len	= ks8851_get_eeprom_len,
  	.get_eeprom	= ks8851_get_eeprom,
  	.set_eeprom	= ks8851_set_eeprom,
  };
  
  /* MII interface controls */
  
  /**
   * ks8851_phy_reg - convert MII register into a KS8851 register
   * @reg: MII register number.
   *
   * Return the KS8851 register number for the corresponding MII PHY register
   * if possible. Return zero if the MII register has no direct mapping to the
   * KS8851 register set.
   */
  static int ks8851_phy_reg(int reg)
  {
  	switch (reg) {
  	case MII_BMCR:
  		return KS_P1MBCR;
  	case MII_BMSR:
  		return KS_P1MBSR;
  	case MII_PHYSID1:
  		return KS_PHY1ILR;
  	case MII_PHYSID2:
  		return KS_PHY1IHR;
  	case MII_ADVERTISE:
  		return KS_P1ANAR;
  	case MII_LPA:
  		return KS_P1ANLPR;
  	}
  
  	return 0x0;
  }
  
  /**
   * ks8851_phy_read - MII interface PHY register read.
   * @dev: The network device the PHY is on.
   * @phy_addr: Address of PHY (ignored as we only have one)
   * @reg: The register to read.
   *
   * This call reads data from the PHY register specified in @reg. Since the
   * device does not support all the MII registers, the non-existent values
   * are always returned as zero.
   *
   * We return zero for unsupported registers as the MII code does not check
   * the value returned for any error status, and simply returns it to the
   * caller. The mii-tool that the driver was tested with takes any -ve error
   * as real PHY capabilities, thus displaying incorrect data to the user.
   */
  static int ks8851_phy_read(struct net_device *dev, int phy_addr, int reg)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	int ksreg;
  	int result;
  
  	ksreg = ks8851_phy_reg(reg);
  	if (!ksreg)
  		return 0x0;	/* no error return allowed, so use zero */
  
  	mutex_lock(&ks->lock);
  	result = ks8851_rdreg16(ks, ksreg);
  	mutex_unlock(&ks->lock);
  
  	return result;
  }
  
  static void ks8851_phy_write(struct net_device *dev,
  			     int phy, int reg, int value)
  {
  	struct ks8851_net *ks = netdev_priv(dev);
  	int ksreg;
  
  	ksreg = ks8851_phy_reg(reg);
  	if (ksreg) {
  		mutex_lock(&ks->lock);
  		ks8851_wrreg16(ks, ksreg, value);
  		mutex_unlock(&ks->lock);
  	}
  }
  
  /**
   * ks8851_read_selftest - read the selftest memory info.
   * @ks: The device state
   *
   * Read and check the TX/RX memory selftest information.
   */
  static int ks8851_read_selftest(struct ks8851_net *ks)
  {
  	unsigned both_done = MBIR_TXMBF | MBIR_RXMBF;
  	int ret = 0;
  	unsigned rd;
  
  	rd = ks8851_rdreg16(ks, KS_MBIR);
  
  	if ((rd & both_done) != both_done) {
  		netdev_warn(ks->netdev, "Memory selftest not finished\n");
  		return 0;
  	}
  
  	if (rd & MBIR_TXMBFA) {
  		netdev_err(ks->netdev, "TX memory selftest fail\n");
  		ret |= 1;
  	}
  
  	if (rd & MBIR_RXMBFA) {
  		netdev_err(ks->netdev, "RX memory selftest fail\n");
  		ret |= 2;
  	}
  
  	return 0;
  }
  
  /* driver bus management functions */
  
  #ifdef CONFIG_PM_SLEEP
  
  static int ks8851_suspend(struct device *dev)
  {
  	struct ks8851_net *ks = dev_get_drvdata(dev);
  	struct net_device *netdev = ks->netdev;
  
  	if (netif_running(netdev)) {
  		netif_device_detach(netdev);
  		ks8851_net_stop(netdev);
  	}
  
  	return 0;
  }
  
  static int ks8851_resume(struct device *dev)
  {
  	struct ks8851_net *ks = dev_get_drvdata(dev);
  	struct net_device *netdev = ks->netdev;
  
  	if (netif_running(netdev)) {
  		ks8851_net_open(netdev);
  		netif_device_attach(netdev);
  	}
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(ks8851_pm_ops, ks8851_suspend, ks8851_resume);
  
  static int ks8851_probe(struct spi_device *spi)
  {
  	struct net_device *ndev;
  	struct ks8851_net *ks;
  	int ret;
  	unsigned cider;
  	int gpio;
  
  	ndev = alloc_etherdev(sizeof(struct ks8851_net));
  	if (!ndev)
  		return -ENOMEM;
  
  	spi->bits_per_word = 8;
  
  	ks = netdev_priv(ndev);
  
  	ks->netdev = ndev;
  	ks->spidev = spi;
  	ks->tx_space = 6144;
  
  	gpio = of_get_named_gpio_flags(spi->dev.of_node, "reset-gpios",
  				       0, NULL);
  	if (gpio == -EPROBE_DEFER) {
  		ret = gpio;
  		goto err_gpio;
  	}
  
  	ks->gpio = gpio;
  	if (gpio_is_valid(gpio)) {
  		ret = devm_gpio_request_one(&spi->dev, gpio,
  					    GPIOF_OUT_INIT_LOW, "ks8851_rst_n");
  		if (ret) {
  			dev_err(&spi->dev, "reset gpio request failed\n");
  			goto err_gpio;
  		}
  	}
  
  	ks->vdd_io = devm_regulator_get(&spi->dev, "vdd-io");
  	if (IS_ERR(ks->vdd_io)) {
  		ret = PTR_ERR(ks->vdd_io);
  		goto err_reg_io;
  	}
  
  	ret = regulator_enable(ks->vdd_io);
  	if (ret) {
  		dev_err(&spi->dev, "regulator vdd_io enable fail: %d\n",
  			ret);
  		goto err_reg_io;
  	}
  
  	ks->vdd_reg = devm_regulator_get(&spi->dev, "vdd");
  	if (IS_ERR(ks->vdd_reg)) {
  		ret = PTR_ERR(ks->vdd_reg);
  		goto err_reg;
  	}
  
  	ret = regulator_enable(ks->vdd_reg);
  	if (ret) {
  		dev_err(&spi->dev, "regulator vdd enable fail: %d\n",
  			ret);
  		goto err_reg;
  	}
  
  	if (gpio_is_valid(gpio)) {
  		usleep_range(10000, 11000);
  		gpio_set_value(gpio, 1);
  	}
  
  	mutex_init(&ks->lock);
  	spin_lock_init(&ks->statelock);
  
  	INIT_WORK(&ks->tx_work, ks8851_tx_work);
  	INIT_WORK(&ks->rxctrl_work, ks8851_rxctrl_work);
  
  	/* initialise pre-made spi transfer messages */
  
  	spi_message_init(&ks->spi_msg1);
  	spi_message_add_tail(&ks->spi_xfer1, &ks->spi_msg1);
  
  	spi_message_init(&ks->spi_msg2);
  	spi_message_add_tail(&ks->spi_xfer2[0], &ks->spi_msg2);
  	spi_message_add_tail(&ks->spi_xfer2[1], &ks->spi_msg2);
  
  	/* setup EEPROM state */
  
  	ks->eeprom.data = ks;
  	ks->eeprom.width = PCI_EEPROM_WIDTH_93C46;
  	ks->eeprom.register_read = ks8851_eeprom_regread;
  	ks->eeprom.register_write = ks8851_eeprom_regwrite;
  
  	/* setup mii state */
  	ks->mii.dev		= ndev;
  	ks->mii.phy_id		= 1,
  	ks->mii.phy_id_mask	= 1;
  	ks->mii.reg_num_mask	= 0xf;
  	ks->mii.mdio_read	= ks8851_phy_read;
  	ks->mii.mdio_write	= ks8851_phy_write;
  
  	dev_info(&spi->dev, "message enable is %d\n", msg_enable);
  
  	/* set the default message enable */
  	ks->msg_enable = netif_msg_init(msg_enable, (NETIF_MSG_DRV |
  						     NETIF_MSG_PROBE |
  						     NETIF_MSG_LINK));
  
  	skb_queue_head_init(&ks->txq);
  
  	ndev->ethtool_ops = &ks8851_ethtool_ops;
  	SET_NETDEV_DEV(ndev, &spi->dev);
  
  	spi_set_drvdata(spi, ks);
  
  	ndev->if_port = IF_PORT_100BASET;
  	ndev->netdev_ops = &ks8851_netdev_ops;
  	ndev->irq = spi->irq;
  
  	/* issue a global soft reset to reset the device. */
  	ks8851_soft_reset(ks, GRR_GSR);
  
  	/* simple check for a valid chip being connected to the bus */
  	cider = ks8851_rdreg16(ks, KS_CIDER);
  	if ((cider & ~CIDER_REV_MASK) != CIDER_ID) {
  		dev_err(&spi->dev, "failed to read device ID\n");
  		ret = -ENODEV;
  		goto err_id;
  	}
  
  	/* cache the contents of the CCR register for EEPROM, etc. */
  	ks->rc_ccr = ks8851_rdreg16(ks, KS_CCR);
  
  	if (ks->rc_ccr & CCR_EEPROM)
  		ks->eeprom_size = 128;
  	else
  		ks->eeprom_size = 0;
  
  	ks8851_read_selftest(ks);
  	ks8851_init_mac(ks);
  
  	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
  				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
  				   ndev->name, ks);
  	if (ret < 0) {
  		dev_err(&spi->dev, "failed to get irq\n");
  		goto err_irq;
  	}
  
  	ret = register_netdev(ndev);
  	if (ret) {
  		dev_err(&spi->dev, "failed to register network device\n");
  		goto err_netdev;
  	}
  
  	netdev_info(ndev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
  		    CIDER_REV_GET(cider), ndev->dev_addr, ndev->irq,
  		    ks->rc_ccr & CCR_EEPROM ? "has" : "no");
  
  	return 0;
  
  
  err_netdev:
  	free_irq(ndev->irq, ks);
  
  err_irq:
  	if (gpio_is_valid(gpio))
  		gpio_set_value(gpio, 0);
  err_id:
  	regulator_disable(ks->vdd_reg);
  err_reg:
  	regulator_disable(ks->vdd_io);
  err_reg_io:
  err_gpio:
  	free_netdev(ndev);
  	return ret;
  }
  
  static int ks8851_remove(struct spi_device *spi)
  {
  	struct ks8851_net *priv = spi_get_drvdata(spi);
  
  	if (netif_msg_drv(priv))
  		dev_info(&spi->dev, "remove\n");
  
  	unregister_netdev(priv->netdev);
  	free_irq(spi->irq, priv);
  	if (gpio_is_valid(priv->gpio))
  		gpio_set_value(priv->gpio, 0);
  	regulator_disable(priv->vdd_reg);
  	regulator_disable(priv->vdd_io);
  	free_netdev(priv->netdev);
  
  	return 0;
  }
  
  static const struct of_device_id ks8851_match_table[] = {
  	{ .compatible = "micrel,ks8851" },
  	{ }
  };
  
  static struct spi_driver ks8851_driver = {
  	.driver = {
  		.name = "ks8851",
  		.of_match_table = ks8851_match_table,
  		.owner = THIS_MODULE,
  		.pm = &ks8851_pm_ops,
  	},
  	.probe = ks8851_probe,
  	.remove = ks8851_remove,
  };
  module_spi_driver(ks8851_driver);
  
  MODULE_DESCRIPTION("KS8851 Network driver");
  MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
  MODULE_LICENSE("GPL");
  
  module_param_named(message, msg_enable, int, 0);
  MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)");
  MODULE_ALIAS("spi:ks8851");
  