/*
   * Hitachi SCA HD64570 driver for Linux
   *
   * Copyright (C) 1998-2003 Krzysztof Halasa <khc@pm.waw.pl>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of version 2 of the GNU General Public License
   * as published by the Free Software Foundation.
   *
   * Source of information: Hitachi HD64570 SCA User's Manual
   *
   * We use the following SCA memory map:
   *
   * Packet buffer descriptor rings - starting from winbase or win0base:
   * rx_ring_buffers * sizeof(pkt_desc) = logical channel #0 RX ring
   * tx_ring_buffers * sizeof(pkt_desc) = logical channel #0 TX ring
   * rx_ring_buffers * sizeof(pkt_desc) = logical channel #1 RX ring (if used)
   * tx_ring_buffers * sizeof(pkt_desc) = logical channel #1 TX ring (if used)
   *
   * Packet data buffers - starting from winbase + buff_offset:
   * rx_ring_buffers * HDLC_MAX_MRU     = logical channel #0 RX buffers
   * tx_ring_buffers * HDLC_MAX_MRU     = logical channel #0 TX buffers
   * rx_ring_buffers * HDLC_MAX_MRU     = logical channel #0 RX buffers (if used)
   * tx_ring_buffers * HDLC_MAX_MRU     = logical channel #0 TX buffers (if used)
   */
  
  #include <linux/bitops.h>
  #include <linux/errno.h>
  #include <linux/fcntl.h>
  #include <linux/hdlc.h>
  #include <linux/in.h>
  #include <linux/interrupt.h>
  #include <linux/ioport.h>
  #include <linux/jiffies.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/netdevice.h>
  #include <linux/skbuff.h>
  #include <linux/string.h>
  #include <linux/types.h>
  #include <asm/io.h>
  #include <asm/uaccess.h>
  #include "hd64570.h"
  
  #define get_msci(port)	  (phy_node(port) ?   MSCI1_OFFSET :   MSCI0_OFFSET)
  #define get_dmac_rx(port) (phy_node(port) ? DMAC1RX_OFFSET : DMAC0RX_OFFSET)
  #define get_dmac_tx(port) (phy_node(port) ? DMAC1TX_OFFSET : DMAC0TX_OFFSET)
  
  #define SCA_INTR_MSCI(node)    (node ? 0x10 : 0x01)
  #define SCA_INTR_DMAC_RX(node) (node ? 0x20 : 0x02)
  #define SCA_INTR_DMAC_TX(node) (node ? 0x40 : 0x04)
  
  
  static inline struct net_device *port_to_dev(port_t *port)
  {
  	return port->dev;
  }
  
  static inline int sca_intr_status(card_t *card)
  {
  	u8 result = 0;
  	u8 isr0 = sca_in(ISR0, card);
  	u8 isr1 = sca_in(ISR1, card);
  
  	if (isr1 & 0x03) result |= SCA_INTR_DMAC_RX(0);
  	if (isr1 & 0x0C) result |= SCA_INTR_DMAC_TX(0);
  	if (isr1 & 0x30) result |= SCA_INTR_DMAC_RX(1);
  	if (isr1 & 0xC0) result |= SCA_INTR_DMAC_TX(1);
  	if (isr0 & 0x0F) result |= SCA_INTR_MSCI(0);
  	if (isr0 & 0xF0) result |= SCA_INTR_MSCI(1);
  
  	if (!(result & SCA_INTR_DMAC_TX(0)))
  		if (sca_in(DSR_TX(0), card) & DSR_EOM)
  			result |= SCA_INTR_DMAC_TX(0);
  	if (!(result & SCA_INTR_DMAC_TX(1)))
  		if (sca_in(DSR_TX(1), card) & DSR_EOM)
  			result |= SCA_INTR_DMAC_TX(1);
  
  	return result;
  }
  
  static inline port_t* dev_to_port(struct net_device *dev)
  {
  	return dev_to_hdlc(dev)->priv;
  }
  
  static inline u16 next_desc(port_t *port, u16 desc, int transmit)
  {
  	return (desc + 1) % (transmit ? port_to_card(port)->tx_ring_buffers
  			     : port_to_card(port)->rx_ring_buffers);
  }
  
  
  static inline u16 desc_abs_number(port_t *port, u16 desc, int transmit)
  {
  	u16 rx_buffs = port_to_card(port)->rx_ring_buffers;
  	u16 tx_buffs = port_to_card(port)->tx_ring_buffers;
  
  	desc %= (transmit ? tx_buffs : rx_buffs); // called with "X + 1" etc.
  	return log_node(port) * (rx_buffs + tx_buffs) +
  		transmit * rx_buffs + desc;
  }
  
  
  static inline u16 desc_offset(port_t *port, u16 desc, int transmit)
  {
  	/* Descriptor offset always fits in 16 bits */
  	return desc_abs_number(port, desc, transmit) * sizeof(pkt_desc);
  }
  
  
  static inline pkt_desc __iomem *desc_address(port_t *port, u16 desc,
  					     int transmit)
  {
  #ifdef PAGE0_ALWAYS_MAPPED
  	return (pkt_desc __iomem *)(win0base(port_to_card(port))
  				    + desc_offset(port, desc, transmit));
  #else
  	return (pkt_desc __iomem *)(winbase(port_to_card(port))
  				    + desc_offset(port, desc, transmit));
  #endif
  }
  
  
  static inline u32 buffer_offset(port_t *port, u16 desc, int transmit)
  {
  	return port_to_card(port)->buff_offset +
  		desc_abs_number(port, desc, transmit) * (u32)HDLC_MAX_MRU;
  }
  
  
  static inline void sca_set_carrier(port_t *port)
  {
  	if (!(sca_in(get_msci(port) + ST3, port_to_card(port)) & ST3_DCD)) {
  #ifdef DEBUG_LINK
  		printk(KERN_DEBUG "%s: sca_set_carrier on
  ",
  		       port_to_dev(port)->name);
  #endif
  		netif_carrier_on(port_to_dev(port));
  	} else {
  #ifdef DEBUG_LINK
  		printk(KERN_DEBUG "%s: sca_set_carrier off
  ",
  		       port_to_dev(port)->name);
  #endif
  		netif_carrier_off(port_to_dev(port));
  	}
  }
  
  
  static void sca_init_port(port_t *port)
  {
  	card_t *card = port_to_card(port);
  	int transmit, i;
  
  	port->rxin = 0;
  	port->txin = 0;
  	port->txlast = 0;
  
  #ifndef PAGE0_ALWAYS_MAPPED
  	openwin(card, 0);
  #endif
  
  	for (transmit = 0; transmit < 2; transmit++) {
  		u16 dmac = transmit ? get_dmac_tx(port) : get_dmac_rx(port);
  		u16 buffs = transmit ? card->tx_ring_buffers
  			: card->rx_ring_buffers;
  
  		for (i = 0; i < buffs; i++) {
  			pkt_desc __iomem *desc = desc_address(port, i, transmit);
  			u16 chain_off = desc_offset(port, i + 1, transmit);
  			u32 buff_off = buffer_offset(port, i, transmit);
  
  			writew(chain_off, &desc->cp);
  			writel(buff_off, &desc->bp);
  			writew(0, &desc->len);
  			writeb(0, &desc->stat);
  		}
  
  		/* DMA disable - to halt state */
  		sca_out(0, transmit ? DSR_TX(phy_node(port)) :
  			DSR_RX(phy_node(port)), card);
  		/* software ABORT - to initial state */
  		sca_out(DCR_ABORT, transmit ? DCR_TX(phy_node(port)) :
  			DCR_RX(phy_node(port)), card);
  
  		/* current desc addr */
  		sca_out(0, dmac + CPB, card); /* pointer base */
  		sca_outw(desc_offset(port, 0, transmit), dmac + CDAL, card);
  		if (!transmit)
  			sca_outw(desc_offset(port, buffs - 1, transmit),
  				 dmac + EDAL, card);
  		else
  			sca_outw(desc_offset(port, 0, transmit), dmac + EDAL,
  				 card);
  
  		/* clear frame end interrupt counter */
  		sca_out(DCR_CLEAR_EOF, transmit ? DCR_TX(phy_node(port)) :
  			DCR_RX(phy_node(port)), card);
  
  		if (!transmit) { /* Receive */
  			/* set buffer length */
  			sca_outw(HDLC_MAX_MRU, dmac + BFLL, card);
  			/* Chain mode, Multi-frame */
  			sca_out(0x14, DMR_RX(phy_node(port)), card);
  			sca_out(DIR_EOME | DIR_BOFE, DIR_RX(phy_node(port)),
  				card);
  			/* DMA enable */
  			sca_out(DSR_DE, DSR_RX(phy_node(port)), card);
  		} else {	/* Transmit */
  			/* Chain mode, Multi-frame */
  			sca_out(0x14, DMR_TX(phy_node(port)), card);
  			/* enable underflow interrupts */
  			sca_out(DIR_BOFE, DIR_TX(phy_node(port)), card);
  		}
  	}
  	sca_set_carrier(port);
  }
  
  
  #ifdef NEED_SCA_MSCI_INTR
  /* MSCI interrupt service */
  static inline void sca_msci_intr(port_t *port)
  {
  	u16 msci = get_msci(port);
  	card_t* card = port_to_card(port);
  	u8 stat = sca_in(msci + ST1, card); /* read MSCI ST1 status */
  
  	/* Reset MSCI TX underrun and CDCD status bit */
  	sca_out(stat & (ST1_UDRN | ST1_CDCD), msci + ST1, card);
  
  	if (stat & ST1_UDRN) {
  		/* TX Underrun error detected */
  		port_to_dev(port)->stats.tx_errors++;
  		port_to_dev(port)->stats.tx_fifo_errors++;
  	}
  
  	if (stat & ST1_CDCD)
  		sca_set_carrier(port);
  }
  #endif
  
  
  static inline void sca_rx(card_t *card, port_t *port, pkt_desc __iomem *desc,
  			  u16 rxin)
  {
  	struct net_device *dev = port_to_dev(port);
  	struct sk_buff *skb;
  	u16 len;
  	u32 buff;
  	u32 maxlen;
  	u8 page;
  
  	len = readw(&desc->len);
  	skb = dev_alloc_skb(len);
  	if (!skb) {
  		dev->stats.rx_dropped++;
  		return;
  	}
  
  	buff = buffer_offset(port, rxin, 0);
  	page = buff / winsize(card);
  	buff = buff % winsize(card);
  	maxlen = winsize(card) - buff;
  
  	openwin(card, page);
  
  	if (len > maxlen) {
  		memcpy_fromio(skb->data, winbase(card) + buff, maxlen);
  		openwin(card, page + 1);
  		memcpy_fromio(skb->data + maxlen, winbase(card), len - maxlen);
  	} else
  		memcpy_fromio(skb->data, winbase(card) + buff, len);
  
  #ifndef PAGE0_ALWAYS_MAPPED
  	openwin(card, 0);	/* select pkt_desc table page back */
  #endif
  	skb_put(skb, len);
  #ifdef DEBUG_PKT
  	printk(KERN_DEBUG "%s RX(%i):", dev->name, skb->len);
  	debug_frame(skb);
  #endif
  	dev->stats.rx_packets++;
  	dev->stats.rx_bytes += skb->len;
  	skb->protocol = hdlc_type_trans(skb, dev);
  	netif_rx(skb);
  }
  
  
  /* Receive DMA interrupt service */
  static inline void sca_rx_intr(port_t *port)
  {
  	struct net_device *dev = port_to_dev(port);
  	u16 dmac = get_dmac_rx(port);
  	card_t *card = port_to_card(port);
  	u8 stat = sca_in(DSR_RX(phy_node(port)), card); /* read DMA Status */
  
  	/* Reset DSR status bits */
  	sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
  		DSR_RX(phy_node(port)), card);
  
  	if (stat & DSR_BOF)
  		/* Dropped one or more frames */
  		dev->stats.rx_over_errors++;
  
  	while (1) {
  		u32 desc_off = desc_offset(port, port->rxin, 0);
  		pkt_desc __iomem *desc;
  		u32 cda = sca_inw(dmac + CDAL, card);
  
  		if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
  			break;	/* No frame received */
  
  		desc = desc_address(port, port->rxin, 0);
  		stat = readb(&desc->stat);
  		if (!(stat & ST_RX_EOM))
  			port->rxpart = 1; /* partial frame received */
  		else if ((stat & ST_ERROR_MASK) || port->rxpart) {
  			dev->stats.rx_errors++;
  			if (stat & ST_RX_OVERRUN)
  				dev->stats.rx_fifo_errors++;
  			else if ((stat & (ST_RX_SHORT | ST_RX_ABORT |
  					  ST_RX_RESBIT)) || port->rxpart)
  				dev->stats.rx_frame_errors++;
  			else if (stat & ST_RX_CRC)
  				dev->stats.rx_crc_errors++;
  			if (stat & ST_RX_EOM)
  				port->rxpart = 0; /* received last fragment */
  		} else
  			sca_rx(card, port, desc, port->rxin);
  
  		/* Set new error descriptor address */
  		sca_outw(desc_off, dmac + EDAL, card);
  		port->rxin = next_desc(port, port->rxin, 0);
  	}
  
  	/* make sure RX DMA is enabled */
  	sca_out(DSR_DE, DSR_RX(phy_node(port)), card);
  }
  
  
  /* Transmit DMA interrupt service */
  static inline void sca_tx_intr(port_t *port)
  {
  	struct net_device *dev = port_to_dev(port);
  	u16 dmac = get_dmac_tx(port);
  	card_t* card = port_to_card(port);
  	u8 stat;
  
  	spin_lock(&port->lock);
  
  	stat = sca_in(DSR_TX(phy_node(port)), card); /* read DMA Status */
  
  	/* Reset DSR status bits */
  	sca_out((stat & (DSR_EOT | DSR_EOM | DSR_BOF | DSR_COF)) | DSR_DWE,
  		DSR_TX(phy_node(port)), card);
  
  	while (1) {
  		pkt_desc __iomem *desc;
  
  		u32 desc_off = desc_offset(port, port->txlast, 1);
  		u32 cda = sca_inw(dmac + CDAL, card);
  		if ((cda >= desc_off) && (cda < desc_off + sizeof(pkt_desc)))
  			break;	/* Transmitter is/will_be sending this frame */
  
  		desc = desc_address(port, port->txlast, 1);
  		dev->stats.tx_packets++;
  		dev->stats.tx_bytes += readw(&desc->len);
  		writeb(0, &desc->stat);	/* Free descriptor */
  		port->txlast = next_desc(port, port->txlast, 1);
  	}
  
  	netif_wake_queue(dev);
  	spin_unlock(&port->lock);
  }
  
  
  static irqreturn_t sca_intr(int irq, void* dev_id)
  {
  	card_t *card = dev_id;
  	int i;
  	u8 stat;
  	int handled = 0;
  	u8 page = sca_get_page(card);
  
  	while((stat = sca_intr_status(card)) != 0) {
  		handled = 1;
  		for (i = 0; i < 2; i++) {
  			port_t *port = get_port(card, i);
  			if (port) {
  				if (stat & SCA_INTR_MSCI(i))
  					sca_msci_intr(port);
  
  				if (stat & SCA_INTR_DMAC_RX(i))
  					sca_rx_intr(port);
  
  				if (stat & SCA_INTR_DMAC_TX(i))
  					sca_tx_intr(port);
  			}
  		}
  	}
  
  	openwin(card, page);		/* Restore original page */
  	return IRQ_RETVAL(handled);
  }
  
  
  static void sca_set_port(port_t *port)
  {
  	card_t* card = port_to_card(port);
  	u16 msci = get_msci(port);
  	u8 md2 = sca_in(msci + MD2, card);
  	unsigned int tmc, br = 10, brv = 1024;
  
  
  	if (port->settings.clock_rate > 0) {
  		/* Try lower br for better accuracy*/
  		do {
  			br--;
  			brv >>= 1; /* brv = 2^9 = 512 max in specs */
  
  			/* Baud Rate = CLOCK_BASE / TMC / 2^BR */
  			tmc = CLOCK_BASE / brv / port->settings.clock_rate;
  		}while (br > 1 && tmc <= 128);
  
  		if (tmc < 1) {
  			tmc = 1;
  			br = 0;	/* For baud=CLOCK_BASE we use tmc=1 br=0 */
  			brv = 1;
  		} else if (tmc > 255)
  			tmc = 256; /* tmc=0 means 256 - low baud rates */
  
  		port->settings.clock_rate = CLOCK_BASE / brv / tmc;
  	} else {
  		br = 9; /* Minimum clock rate */
  		tmc = 256;	/* 8bit = 0 */
  		port->settings.clock_rate = CLOCK_BASE / (256 * 512);
  	}
  
  	port->rxs = (port->rxs & ~CLK_BRG_MASK) | br;
  	port->txs = (port->txs & ~CLK_BRG_MASK) | br;
  	port->tmc = tmc;
  
  	/* baud divisor - time constant*/
  	sca_out(port->tmc, msci + TMC, card);
  
  	/* Set BRG bits */
  	sca_out(port->rxs, msci + RXS, card);
  	sca_out(port->txs, msci + TXS, card);
  
  	if (port->settings.loopback)
  		md2 |= MD2_LOOPBACK;
  	else
  		md2 &= ~MD2_LOOPBACK;
  
  	sca_out(md2, msci + MD2, card);
  
  }
  
  
  static void sca_open(struct net_device *dev)
  {
  	port_t *port = dev_to_port(dev);
  	card_t* card = port_to_card(port);
  	u16 msci = get_msci(port);
  	u8 md0, md2;
  
  	switch(port->encoding) {
  	case ENCODING_NRZ:	md2 = MD2_NRZ;		break;
  	case ENCODING_NRZI:	md2 = MD2_NRZI;		break;
  	case ENCODING_FM_MARK:	md2 = MD2_FM_MARK;	break;
  	case ENCODING_FM_SPACE:	md2 = MD2_FM_SPACE;	break;
  	default:		md2 = MD2_MANCHESTER;
  	}
  
  	if (port->settings.loopback)
  		md2 |= MD2_LOOPBACK;
  
  	switch(port->parity) {
  	case PARITY_CRC16_PR0:	     md0 = MD0_HDLC | MD0_CRC_16_0;  break;
  	case PARITY_CRC16_PR1:	     md0 = MD0_HDLC | MD0_CRC_16;    break;
  	case PARITY_CRC16_PR0_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU_0; break;
  	case PARITY_CRC16_PR1_CCITT: md0 = MD0_HDLC | MD0_CRC_ITU;   break;
  	default:		     md0 = MD0_HDLC | MD0_CRC_NONE;
  	}
  
  	sca_out(CMD_RESET, msci + CMD, card);
  	sca_out(md0, msci + MD0, card);
  	sca_out(0x00, msci + MD1, card); /* no address field check */
  	sca_out(md2, msci + MD2, card);
  	sca_out(0x7E, msci + IDL, card); /* flag character 0x7E */
  	sca_out(CTL_IDLE, msci + CTL, card);
  
  	/* Allow at least 8 bytes before requesting RX DMA operation */
  	/* TX with higher priority and possibly with shorter transfers */
  	sca_out(0x07, msci + RRC, card); /* +1=RXRDY/DMA activation condition*/
  	sca_out(0x10, msci + TRC0, card); /* = TXRDY/DMA activation condition*/
  	sca_out(0x14, msci + TRC1, card); /* +1=TXRDY/DMA deactiv condition */
  
  /* We're using the following interrupts:
     - TXINT (DMAC completed all transmisions, underrun or DCD change)
     - all DMA interrupts
  */
  	sca_set_carrier(port);
  
  	/* MSCI TX INT and RX INT A IRQ enable */
  	sca_out(IE0_TXINT | IE0_RXINTA, msci + IE0, card);
  	sca_out(IE1_UDRN | IE1_CDCD, msci + IE1, card);
  	sca_out(sca_in(IER0, card) | (phy_node(port) ? 0xC0 : 0x0C),
  		IER0, card); /* TXINT and RXINT */
  	/* enable DMA IRQ */
  	sca_out(sca_in(IER1, card) | (phy_node(port) ? 0xF0 : 0x0F),
  		IER1, card);
  
  	sca_out(port->tmc, msci + TMC, card); /* Restore registers */
  	sca_out(port->rxs, msci + RXS, card);
  	sca_out(port->txs, msci + TXS, card);
  	sca_out(CMD_TX_ENABLE, msci + CMD, card);
  	sca_out(CMD_RX_ENABLE, msci + CMD, card);
  
  	netif_start_queue(dev);
  }
  
  
  static void sca_close(struct net_device *dev)
  {
  	port_t *port = dev_to_port(dev);
  	card_t* card = port_to_card(port);
  
  	/* reset channel */
  	sca_out(CMD_RESET, get_msci(port) + CMD, port_to_card(port));
  	/* disable MSCI interrupts */
  	sca_out(sca_in(IER0, card) & (phy_node(port) ? 0x0F : 0xF0),
  		IER0, card);
  	/* disable DMA interrupts */
  	sca_out(sca_in(IER1, card) & (phy_node(port) ? 0x0F : 0xF0),
  		IER1, card);
  
  	netif_stop_queue(dev);
  }
  
  
  static int sca_attach(struct net_device *dev, unsigned short encoding,
  		      unsigned short parity)
  {
  	if (encoding != ENCODING_NRZ &&
  	    encoding != ENCODING_NRZI &&
  	    encoding != ENCODING_FM_MARK &&
  	    encoding != ENCODING_FM_SPACE &&
  	    encoding != ENCODING_MANCHESTER)
  		return -EINVAL;
  
  	if (parity != PARITY_NONE &&
  	    parity != PARITY_CRC16_PR0 &&
  	    parity != PARITY_CRC16_PR1 &&
  	    parity != PARITY_CRC16_PR0_CCITT &&
  	    parity != PARITY_CRC16_PR1_CCITT)
  		return -EINVAL;
  
  	dev_to_port(dev)->encoding = encoding;
  	dev_to_port(dev)->parity = parity;
  	return 0;
  }
  
  
  #ifdef DEBUG_RINGS
  static void sca_dump_rings(struct net_device *dev)
  {
  	port_t *port = dev_to_port(dev);
  	card_t *card = port_to_card(port);
  	u16 cnt;
  #ifndef PAGE0_ALWAYS_MAPPED
  	u8 page = sca_get_page(card);
  
  	openwin(card, 0);
  #endif
  
  	printk(KERN_DEBUG "RX ring: CDA=%u EDA=%u DSR=%02X in=%u %sactive",
  	       sca_inw(get_dmac_rx(port) + CDAL, card),
  	       sca_inw(get_dmac_rx(port) + EDAL, card),
  	       sca_in(DSR_RX(phy_node(port)), card), port->rxin,
  	       sca_in(DSR_RX(phy_node(port)), card) & DSR_DE ? "" : "in");
  	for (cnt = 0; cnt < port_to_card(port)->rx_ring_buffers; cnt++)
  		pr_cont(" %02X", readb(&(desc_address(port, cnt, 0)->stat)));
  	pr_cont("
  ");
  
  	printk(KERN_DEBUG "TX ring: CDA=%u EDA=%u DSR=%02X in=%u "
  	       "last=%u %sactive",
  	       sca_inw(get_dmac_tx(port) + CDAL, card),
  	       sca_inw(get_dmac_tx(port) + EDAL, card),
  	       sca_in(DSR_TX(phy_node(port)), card), port->txin, port->txlast,
  	       sca_in(DSR_TX(phy_node(port)), card) & DSR_DE ? "" : "in");
  
  	for (cnt = 0; cnt < port_to_card(port)->tx_ring_buffers; cnt++)
  		pr_cont(" %02X", readb(&(desc_address(port, cnt, 1)->stat)));
  	pr_cont("
  ");
  
  	printk(KERN_DEBUG "MSCI: MD: %02x %02x %02x, ST: %02x %02x %02x %02x,"
  	       " FST: %02x CST: %02x %02x
  ",
  	       sca_in(get_msci(port) + MD0, card),
  	       sca_in(get_msci(port) + MD1, card),
  	       sca_in(get_msci(port) + MD2, card),
  	       sca_in(get_msci(port) + ST0, card),
  	       sca_in(get_msci(port) + ST1, card),
  	       sca_in(get_msci(port) + ST2, card),
  	       sca_in(get_msci(port) + ST3, card),
  	       sca_in(get_msci(port) + FST, card),
  	       sca_in(get_msci(port) + CST0, card),
  	       sca_in(get_msci(port) + CST1, card));
  
  	printk(KERN_DEBUG "ISR: %02x %02x %02x
  ", sca_in(ISR0, card),
  	       sca_in(ISR1, card), sca_in(ISR2, card));
  
  #ifndef PAGE0_ALWAYS_MAPPED
  	openwin(card, page); /* Restore original page */
  #endif
  }
  #endif /* DEBUG_RINGS */
  
  
  static netdev_tx_t sca_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	port_t *port = dev_to_port(dev);
  	card_t *card = port_to_card(port);
  	pkt_desc __iomem *desc;
  	u32 buff, len;
  	u8 page;
  	u32 maxlen;
  
  	spin_lock_irq(&port->lock);
  
  	desc = desc_address(port, port->txin + 1, 1);
  	BUG_ON(readb(&desc->stat)); /* previous xmit should stop queue */
  
  #ifdef DEBUG_PKT
  	printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
  	debug_frame(skb);
  #endif
  
  	desc = desc_address(port, port->txin, 1);
  	buff = buffer_offset(port, port->txin, 1);
  	len = skb->len;
  	page = buff / winsize(card);
  	buff = buff % winsize(card);
  	maxlen = winsize(card) - buff;
  
  	openwin(card, page);
  	if (len > maxlen) {
  		memcpy_toio(winbase(card) + buff, skb->data, maxlen);
  		openwin(card, page + 1);
  		memcpy_toio(winbase(card), skb->data + maxlen, len - maxlen);
  	} else
  		memcpy_toio(winbase(card) + buff, skb->data, len);
  
  #ifndef PAGE0_ALWAYS_MAPPED
  	openwin(card, 0);	/* select pkt_desc table page back */
  #endif
  	writew(len, &desc->len);
  	writeb(ST_TX_EOM, &desc->stat);
  
  	port->txin = next_desc(port, port->txin, 1);
  	sca_outw(desc_offset(port, port->txin, 1),
  		 get_dmac_tx(port) + EDAL, card);
  
  	sca_out(DSR_DE, DSR_TX(phy_node(port)), card); /* Enable TX DMA */
  
  	desc = desc_address(port, port->txin + 1, 1);
  	if (readb(&desc->stat)) /* allow 1 packet gap */
  		netif_stop_queue(dev);
  
  	spin_unlock_irq(&port->lock);
  
  	dev_kfree_skb(skb);
  	return NETDEV_TX_OK;
  }
  
  
  #ifdef NEED_DETECT_RAM
  static u32 sca_detect_ram(card_t *card, u8 __iomem *rambase, u32 ramsize)
  {
  	/* Round RAM size to 32 bits, fill from end to start */
  	u32 i = ramsize &= ~3;
  	u32 size = winsize(card);
  
  	openwin(card, (i - 4) / size); /* select last window */
  
  	do {
  		i -= 4;
  		if ((i + 4) % size == 0)
  			openwin(card, i / size);
  		writel(i ^ 0x12345678, rambase + i % size);
  	} while (i > 0);
  
  	for (i = 0; i < ramsize ; i += 4) {
  		if (i % size == 0)
  			openwin(card, i / size);
  
  		if (readl(rambase + i % size) != (i ^ 0x12345678))
  			break;
  	}
  
  	return i;
  }
  #endif /* NEED_DETECT_RAM */
  
  
  static void sca_init(card_t *card, int wait_states)
  {
  	sca_out(wait_states, WCRL, card); /* Wait Control */
  	sca_out(wait_states, WCRM, card);
  	sca_out(wait_states, WCRH, card);
  
  	sca_out(0, DMER, card);	/* DMA Master disable */
  	sca_out(0x03, PCR, card); /* DMA priority */
  	sca_out(0, DSR_RX(0), card); /* DMA disable - to halt state */
  	sca_out(0, DSR_TX(0), card);
  	sca_out(0, DSR_RX(1), card);
  	sca_out(0, DSR_TX(1), card);
  	sca_out(DMER_DME, DMER, card); /* DMA Master enable */
  }